System and method for fuel savings and safe operation of marine structure

ABSTRACT

A system for monitoring a physical change of a marine structure includes a complex optical measuring instrument configured to detect a behavior and structural change of the marine structure by using at least one optical sensor by means of optical fiber Bragg grating.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/KR2013/004777 filed on May 30, 2013, which claims priority to KoreanApplication No. 10-2012-0057753 filed on May 30, 2012, KoreanApplication No. 10-2012-0057754 filed on May 30, 2012, KoreanApplication No. 10-2012-0057755 filed on May 30, 2012, KoreanApplication No. 10-2012-0129441 filed on Nov. 15, 2012, KoreanApplication No. 10-2012-0149412 filed on Dec. 20, 2012, KoreanApplication No. 10-2012-0149411 filed on Dec. 20, 2012, KoreanApplication No. 10-2013-0061759 filed on May 30, 2013, KoreanApplication No. 10-2013-0061477 filed on May 30, 2013, and KoreanApplication No. 10-2013-0061754 filed on May 30, 2013. The applicationsare incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a system and method for monitoringphysical changes of a marine structure in real time with a complexoptical measuring instrument by using an optical sensor type measurementmethod. More particularly, the present disclosure relates to a systemand method for monitoring physical changes of a marine structure in realtime with a complex optical measuring instrument by using an opticalsensor type measurement method.

In addition, the present disclosure also relates to real-time predictivemonitoring and predictive controlling of aerodynamic and hydrodynamicenvironmental internal or external force, hull stresses, 6 degrees offreedom (6-dof) movement and location of a marine structure, and moreparticularly, to a method for synthetically measuring changes offour-directional slopes, sea gauge, trim, corrosion, erosion, crack,pressure, stress, vibration, frequency or the like applied to a floatingmarine structure by means of aerodynamic and hydrodynamic environmentalinternal or external force, and controlling the marine structure basedthereon to provide information on fuel savings, safe operation andmaintenance.

The present disclosure also relates to a method for controlling astructure (e.g., a marine/land structure, a shipbuilding structure, anaerospace structure, an underwater mooring structure, a fixed orwind/tide/wave-based structure or the like) by means of integralmonitoring of environmental external forces.

BACKGROUND ART

Crude oil produced at a marine oil well is carried to a marine structureby using a pipeline which is a kind of a marine structure. The marinestructure includes a floating production storage and offloading (FPSO),a tension-leg platform (TLP), a semi-submersible (SPAR), a fixe platformor the like.

At this time, the pipeline is installed in a deep sea as much as severalkilometers to several hundred kilometers for the purpose of over 20-yearoperations.

In this case, the pipeline installed in a deep sea is shrunken orexpanded by a temperature deviation over 100 degrees, and physicalchanges such as a length change occur due to a pressure change in thepipeline.

Accordingly, in the pipeline installed at the sea, stresses areintensively generated at a plurality of specific or unspecified points,which results in buckling or deformation. In addition, in a touch downzone where a pipeline installed at the seabed is connected to a riserserving as a marine carrier, the pipeline may pitch and roll due to aplurality of external environmental forces such as sea current, wave,tidal current, wind, temperature or the like.

In order to measure such pitch and roll, various kinds of monitoringmethods are being used at the present. In an existing monitoring method,a deformation rate of the pipeline is measured by using an electric-typeor optical fiber-type deformation sensor. In a marine structure, awelding portion is most vulnerable in a structural aspect, and thussensors are installed and operated at intervals of 20 to 50 cm. Here,sensors are installed in a length direction of the pipeline to analyzedeformation. In another monitoring method, an electric-type inclinometeris used to detect deformation of the pipeline.

However, such existing monitoring methods have difficulty in accuratelyanalyzing situations since a deformation rate caused by temperature orpressure of a marine structure is much greater than a deformation ratecaused by buckling or walking. In addition, an electric-typeinclinometer currently used is installed in the sea and thus hasproblems such as loss by water leak caused by high hydraulic pressureand complexity in its power supply device and connection method, andthus a new measurement method allowing easier use is demanded. Inaddition, sensors used in the existing monitoring methods have shortfatigue measurement durability life, and thus sensors useable for alonger time are needed.

During operation of a marine structure, fluid flow inevitably applies aninternal or external force to the marine structure. Particularly, incase of a fixed marine structure mooring at a specific point on the sea,it is essential to control so that the internal or external force causedby such fluid flow is minimized.

In addition, during operation of a marine structure, aerodynamic andhydrodynamic environmental internal or external force and hull stressesmay cause turnover of a ship or fall of cargos, and this problem shouldbe solved urgently.

Meanwhile, it is an essence in the future marine shipbuilding industryto develop and build a marine structure having low fuel consumption.Assuming that marine structures consume 100 tons of fuel and exhaust 320tons of carbon dioxide, if the fuel efficiency is improved by 1%, costsmay be reduced over 240,000 dollars per year, about 6 million dollarsfor 24 years. In the used ship market, the fuel efficiency is one of themost important factors.

In addition, the modern society mostly depends on motorizedtransportation systems which exhaust greenhouse gas, but it is widelyknown that exhaustion of CO2 is a main cause of global warming, climatechange and ocean acidification. In view of the amount of CO2 exhaustedfor transporting 1 ton of cargo by 1 mile, a marine structure is mostefficient among all kinds of transportation means. However, since marinestructures are overwhelming transportation means in the world trade, theamount of exhausted CO2 by marine structures occupies about 3% in theentire greenhouse gas exhaustion. Therefore, if the fuel efficiency ofmarine structures is enhanced, the amount of exhausted greenhouse gas inthe industry may be greatly reduced.

In addition, existing manual or semi-automated marine make a largedifference in their operations due to the skill level of workers, and asystem developed to use a semi-automation mode may be applied just to acorresponding marine structure. Therefore, in order to implement asystem inclusively applied to various kinds of ships, a softwareengineering approach is required, and a software framework for providinga basis for developing similar kinds of applications should bedeveloped.

SUMMARY

The present disclosure is designed to solve the problems of the relatedart, and therefore the present disclosure is directed to providing amethod for fuel savings by real-time monitoring and controlling ofaerodynamic and hydrodynamic environmental internal or external force,hull stresses, 6 degrees of freedom (6-doe movement and location of amarine structure.

In addition, the present disclosure is directed to providing amonitoring system and method which may allow long-term measurement of achange of a marine structure by using an optical sensor-type complexmeasurement, in comparison to an existing electric sensor-typemeasurement, and also ensure convenient installation and operation.

Moreover, the present disclosure is directed to providing an environmentin which the monitoring information may be shared with another externaldevice to enhance the accuracy of weather information, and data measuredby satellites may be calibrated.

In addition, the present disclosure is directed to providing a methodfor real-time safe operation by measuring a change of four-directionalslopes, sea gauge, trim or the like applied to a floating marinestructure by means of aerodynamic and hydrodynamic environmentalinternal or external force, and then controlling the floating marinestructure based on the measurement result.

Moreover, the present disclosure is directed to providing information onmaintenance in real time by measuring corrosion, erosion, crack,pressure, stress or the like caused by aerodynamic and hydrodynamicenvironmental internal or external force applied to the marinestructure.

The present disclosure is designed to solve the problems of the relatedart, and therefore the present disclosure is directed to providing amethod for fuel savings by real-time monitoring and controlling ofaerodynamic and hydrodynamic environmental internal or external force,hull stresses, 6-dof motion and location of a marine structure.

In addition, the present disclosure is directed to providing amonitoring system and method which may allow long-term measurement of achange of a marine structure by using an optical sensor-type complexmeasurement, in comparison to an existing electric sensor-typemeasurement, and also ensures convenient installation and operation.

Moreover, the present disclosure is directed to providing an environmentin which the monitoring information may be shared with another externaldevice to enhance the accuracy of weather information, and data measuredby satellites may be calibrated.

In addition, the present disclosure is directed to providing a methodfor real-time safe operation by measuring a change of four-directionalslopes, sea gauge, trim or the like applied to a floating marinestructure by means of aerodynamic and hydrodynamic environmentalinternal or external force, and then controlling the floating marinestructure based on the measurement result.

Moreover, the present disclosure is directed to providing information onmaintenance in real time by measuring corrosion, erosion, crack,pressure, stress or the like caused by aerodynamic and hydrodynamicenvironmental internal or external force applied to the marinestructure.

In one aspect of the present disclosure, there is provided a system formonitoring a physical change of a marine structure, which includes acomplex optical measuring instrument configured to detect a behavior andstructural change of the marine structure by using at least one opticalsensor by means of optical fiber Bragg grating.

In addition, the complex optical measuring instrument may include anextensometer for measuring a distance change between at least onereference point set out of the marine structure and a point set on themarine structure by using the optical sensor, and the optical sensor maychange a wavelength of the optical signal passing through the opticalsensor according to a stress change applied to an optical fiber by thedistance change.

The extensometer may include at least one wire for connecting thereference point and a point set on the marine structure. In addition,the wire may include an invar. In addition, the extensometer may furtherinclude a winding unit for winding the wire by a predetermined tension;and a sensing unit for measuring the number of revolutions of thewinding unit by using an optical sensor. In addition, the extensometermay further include a stimulating unit for periodically stimulating theoptical sensor according to the number of revolutions measured by thesensing unit.

In addition, according to another embodiment of the present disclosure,the complex optical measuring instrument may include an extensometerhaving an optical fiber wire 320 for connecting at least one point onthe marine structure to measure a length change of the marine structure.The optical fiber wire 320 may change a wavelength of the optical signalpassing through the optical fiber according to a stress change appliedto an optical sensor due to a distance change on the marine structure.

In addition, according to another embodiment of the present disclosure,the extensometer may include at least one wire installed on the samepoint on the marine structure and made of an optical fiber, and the wiremay change a wavelength of the optical signal passing through theoptical fiber according to a stress change applied to an optical sensordue to a distance change on the marine structure.

In addition, according to another embodiment of the present disclosure,the extensometer may provide absolute location information of the pointby calculating the degree of tension of each wire by means of thetrigonometrical survey.

In addition, according to another embodiment of the present disclosure,the complex optical measuring instrument may include an inclinometer formeasuring an angle change among a plurality of points on the marinestructure by using the optical sensor. In addition, the inclinometer mayinclude a weight installed in the gravity direction; and an opticalsensor connected to the weight and having at least one optical fiber,and due to the angle change of the point on the marine structure wherethe inclinometer is installed, a wavelength of the optical signalpassing through the optical fiber may be changed according to a stresschange applied to the optical fiber by means of the weight.

In addition, according to another embodiment of the present disclosure,the complex optical measuring instrument may further include aseismometer for measuring a location change of the reference point. Inaddition, the complex optical measuring instrument may further include avibration gauge for measuring a vibration of the marine structure.

In addition, according to another embodiment of the present disclosure,the system may further include a measurement device for detecting achange of the wavelength of the optical signal by the complex opticalmeasuring instrument. The measurement device may be a data logger or aninterrogator.

In addition, according to another embodiment of the present disclosure,the complex optical measuring instrument may detect a change of a targetstructure by using at least one of optical time-domain reflectometer(OTDR), Raman spectra (Raman), Brillouin scattering, Rayleigh wave,distributed acoustic sensing (DAS), acoustic emission, andinterferometry.

In addition, according to another embodiment of the present disclosure,the measurement device may include an optical unit having a lasercapable of controlling a wavelength; an optical referencing unit fordistinguishing a wavelength of the optical signal reflected by theoptical unit by means of each optical sensor; an optical coupler forconnecting a plurality of optical fiber Bragg gratings of each opticalsensor output from the optical referencing unit and distributing a Braggreflection wavelength to each channel; and a photodiode for convertingthe Bragg reflection wavelength received from the optical coupler intoan electric signal. In addition, the measurement device may have afunction of collecting scattered optical signals.

Meanwhile, in another aspect of the present disclosure, there is alsoprovided a method for monitoring a physical change of a marinestructure, which includes (a) changing a wavelength or light quantity ofthe optical signal passing through an optical sensor according to abehavior or structural change of a marine structure by using at leastone complex optical measuring instrument installed on the marinestructure or a reference point; (b) by the complex optical measuringinstrument, transmitting the optical signal having the changedwavelength or light quantity to the measurement device; and (c) by themeasurement device, detecting a change of the wavelength or lightquantity of the optical signal, wherein the complex optical measuringinstrument includes at least one optical sensor using optical fiberBragg grating.

In addition, according to another embodiment of the present disclosure,the complex optical measuring instrument may include an extensometer formeasuring a distance change between at least one reference point set outof the marine structure and a point set on the marine structure.

In addition, according to another embodiment of the present disclosure,the extensometer may further include at least one wire connecting thereference point and a point set on the marine structure; a winding unitfor winding the wire by a predetermined tension; a sensing unit formeasuring the number of revolutions of the winding unit by using anoptical sensor; and a stimulating unit for periodically stimulating theoptical fiber according to the number of revolutions measured by thesensing unit.

In addition, according to another embodiment of the present disclosure,the extensometer may include an optical fiber wire for connecting atleast one point on the marine structure to measure a length change ofthe marine structure, and the optical fiber wire may change a wavelengthof the optical signal passing through the optical fiber according to astress change due to a distance change on the marine structure.

In addition, according to another embodiment of the present disclosure,the extensometer may include at least one wire installed on the samepoint on the marine structure and made of an optical fiber, and the wiremay change a wavelength of the optical signal passing through theoptical fiber according to a stress change applied to the optical fiberdue to a distance change on the marine structure.

In addition, according to another embodiment of the present disclosure,the extensometer may provide absolute location information of the pointby calculating the degree of tension of each wire by means of thetrigonometrical survey.

In addition, according to another embodiment of the present disclosure,the complex optical measuring instrument may include an inclinometer formeasuring an angle change among a plurality of points on the marinestructure by using the optical sensor. The inclinometer may include aweight installed in the gravity direction; and an optical sensorconnected to the weight, and in the step (a), the weight may simulatethe optical fiber according to an angle change occurring at the marinestructure to generate a stress change, and the generated stress changeis converted into an optical signal.

In addition, according to another embodiment of the present disclosure,the complex optical measuring instrument may further include aseismometer for measuring a location change of at least one referencepoint set out of the marine structure by using the optical sensor.

In addition, according to another embodiment of the present disclosure,the complex optical measuring instrument may further include a vibrationgauge for measuring a vibration of the marine structure.

In addition, according to another embodiment of the present disclosure,the measurement device may use a data logger or an interrogator.

In addition, according to another embodiment of the present disclosure,the measurement device may include an optical unit having a lasercapable of controlling a wavelength; an optical referencing unit fordistinguishing a wavelength of the optical signal reflected by theoptical unit by means of each optical sensor; an optical coupler forconnecting a plurality of optical fiber Bragg gratings of each opticalsensor output from the optical referencing unit and distributing a Braggreflection wavelength to each channel; and a photodiode for convertingthe Bragg reflection wavelength received from the optical coupler intoan electric signal.

Meanwhile, in another aspect of the present disclosure, there is alsoprovided a controlling method by real-time monitoring of a physicalchange of a marine structure, which includes (a) obtaining data about aphysical change of a marine structure through experiments at a watertank or a wind tunnel and accumulating the obtained data to generate alook-up table; (b) obtaining about an actual physical change of themarine structure, output from a measurement device; (c) comparing thedata obtained in the step (b) with the data accumulated in the look-uptable of the step (a) to generate forecasting data about the physicalchange of the marine structure; and (d) generating maintenanceinformation including at least one of structure controlling operationinformation, maintenance-required location information, maintenance costinformation and required maintenance time and alarm information aboutgas leak, fire or explosion by means of a three-dimensional numericalanalysis program which receives the forecasting data, wherein thephysical change includes at least one of a length change, an anglechange, a temperature change, a pressure change and a specific volumechange about at least one point on the marine structure.

In addition, according to another embodiment of the present disclosure,after the step (c), the method may further include (c-1) comparing theforecasting data with data about an actual physical change of the marinestructure to correct the look-up table.

In addition, according to another embodiment of the present disclosure,after the step (d), the method may further include generating asimulator with the marine structure control information by means of afluid structure interaction (FSI) program, and associating the simulatorwith the data about an actual physical change of the marine structure,obtained in the step (b), by means of context cognitive middleware togenerate an algorithm for automatically controlling the marinestructure.

In addition, according to another embodiment of the present disclosure,the three-dimensional numerical analysis program of the step (d) may usefinite element method (FEM) and computational fluid dynamics (CFD).

In addition, according to another embodiment of the present disclosure,in the step (d), the three-dimensional numerical analysis program may beassociated with a situation analysis module which stores virtualaugmented reality data about information including gas leak, gasdiffusion, fire or explosion, which probably occurs according to abehavior and structural change of the marine structure, andcountermeasures against the virtual augmented reality data, to generatemaintenance information.

In addition, according to another embodiment of the present disclosure,the method may further include (e) by an automatic structure controlunit, controlling the marine structure by changing a location or angleof the marine structure according to the control operation information,and the automatic structure control unit may include a coupling unitconnected to at least one point on the marine structure; and a displaceadjusting unit connected to the coupling unit to move the marinestructure in four directions.

In addition, the alarm information may be generated by using the dataabout an actual physical change of the marine structure, which ismeasured by the measurement device by using at least one of tunablediode laser absorption spectroscopy (TDLAS), distributed temperaturesensing (DTS), distributed acoustic sensing (DAS), fiber Bragg grating(FBG) and remote methane leak detector (RMLD).

Meanwhile, in another aspect of the present disclosure, there is alsoprovided a method for fuel savings and safe operation by real-timepredictive monitoring and predictive controlling of aerodynamicenvironmental internal or external force, hull stresses, 6 degrees offreedom (6-dof) movement and location of a marine structure, the methodincluding: (1) accumulating data about an internal or external forceapplied to a marine structure by a gas flow out of the marine structureby means of a linear test (e.g., hull form test) in a water tank or awind tunnel and data about a response of the marine structure accordingto the internal or external force to generate a look-up table, andstoring the look-up table in a database; (2) measuring the internal orexternal force by using a time-of-flight method in an actual voyage ofthe marine structure and storing the internal or external force in thedatabase; (3) comparing the measurement data of the internal or externalforce obtained in the step (2) with the data about the internal orexternal force accumulated in the look-up table in the step (1) topredict data about a response of the marine structure; and (4)controlling a posture or navigation path of the marine structure in realtime by using the predicted data about a response of the marinestructure.

In addition, the step (3) may include (3-1) measuring an actual responseof the marine structure; and (3-2) when the data about a response of themarine structure measured in the step (3-1) does not agree with the dataabout a response of the marine structure predicted in the step (3),correcting the data about a response of the marine structure stored inthe look-up table generated in the step (1) into the data about aresponse of the marine structure measured in the step (3-1) or applyingthe corrected data to correct or supplement a numerical model.

In this case, the data about a response of the marine structure may becorrected by means of a simulator based on finite element analysis(FEA).

In addition, in the step (2), the internal or external force caused bygas may be measured by using a measurement instrument provided at themarine structure, and the measurement instrument may be an electricsensor or an optical sensor. In addition, the measurement instrument maymeasure wind direction, wind velocity, atmospheric pressure,temperature, humidity and dust at each altitude.

In addition, in the step (2), the internal or external force applied tothe marine structure by a gas flow may be actually measured by using aninternal measurement unit (IMU).

In addition, in the step (3), when the marine structure is a ship, thedata about a response of the marine structure may include at least oneselected from the group consisting of progress direction,four-directional slopes, sea gauge and trim of the ship.

In addition, in the step (3), when the marine structure is a temporarilyfixed structure, the data about a response of the marine structure mayinclude at least one selected from the group consisting of movingdirection, four-directional slopes and sea gauge of the temporarilyfixed structure.

In addition, in the step (2), data including natural frequency, harmonicfrequency and gas characteristics of the marine structure by a gas flowmay be measured.

In addition, in the step (1), the database storing the look-up table maybe a voyage data recorder (VDR) provided at the marine structure.

In addition, when the marine structure is a temporarily fixed structure,the look-up table may be recorded as time sequential data by the year,and the look-up table may be corrected by comparing with time sequentialdata by the year which have been accumulated till the previous year.

In addition, in the step (4), the posture or navigation path of themarine structure may be controlled in real time by using at least oneselected from the group consisting of a rudder, a thruster, a propeller,a sail, a kite and a balloon.

In addition, in the step (4), when the marine structure is a ship, adirection of a rudder or a RPM of a thruster or propeller may becontrolled according to the data about a response of the marinestructure so that a resultant force of a propelling force and theinternal or external force has a targeted progress direction.

In addition, when the marine structure is a temporarily fixed structure,a thruster may be controlled according to the predicted data about aresponse of the marine structure so that a resultant force with theinternal or external force is minimized to maintain a current location.

In addition, the marine structure may include a helideck, and in thestep (4), a center of gravity of the marine structure may be changed bycontrolling a posture of the marine structure or adjusting an 6-dofangle by means of dynamic positioning (DP) or dynamic motioning (DM) soas to maintain a balance of the helideck or relieve a shock when ahelicopter takes off or lands, and balanced state information of thehelideck is stored in the database. In addition, the balanced stateinformation of the helideck obtained by controlling a posture of themarine structure may be stored in the database, the database maytransmit the balanced state information of the helideck to an externalstructure information server by means of a communication unit, and thestructure information server may provide the helicopter with locationinformation of a marine structure, which has the balanced stateinformation of the helideck allowing taking-off or landing of ahelicopter, among a plurality of marine structures.

In addition, the step (2) may further include (2-1) measuring at leastone selected from the group consisting of wind direction, wind velocity,temperature, humidity, atmospheric pressure, solar radiant rays,inorganic ions, carbon dioxide, dust, radioactivity and ozone at aremote distance from the marine structure by using a measurementinstrument, and storing the measurement data in the database.

Here, the measurement instrument may include at least one selected fromthe group consisting of an anemometer, a weathervane, a hygrometer, athermometer, a barometer, a solarimeter, an atmospheric gassol automaticcollector, a CO2 flux measurement instrument, an atmospheric dustcollector, an air sampler and an ozone analyzer.

In addition, the marine structure may include a ballast tank, andsloshing restraining units may be respectively provided at both sides ofthe ballast tank to reduce a sloshing phenomenon in the ballast tank. Inaddition, the sloshing restraining unit may restrain a sloshingphenomenon by decreasing an opening area of one horizontal section ofthe ballast tank.

In addition, in the step (4), ballast water loaded in the ballast tankmay be moved in a direction opposite to a slope to control a posture ofthe marine structure. In addition, the ballast tank may include abarrier for partitioning an inside of the ballast tank, anopening/closing unit may be installed at the barrier to move the ballastwater to another partition, and a pump may be installed in theopening/closing unit to control a moving speed and a moving direction ofthe ballast water.

In addition, the measurement data of the internal or external forceobtained in the step (2) may be transmitted to an external weatherinformation server, and the weather information server may store weatherinformation correction data whose error is corrected by comparingweather information received from a satellite with the measurement dataof the internal or external force.

In addition, the weather information correction data may be provided toan external user terminal which accesses the weather information serveraccording to a request of the external user terminal.

Meanwhile, in another aspect of the present disclosure, there is alsoprovided a method for providing maintenance information by real-timepredictive monitoring of aerodynamic environmental internal or externalforce, hull stresses, 6-dof motion and location of a marine structure,the method including: (1) accumulating data about an internal orexternal force applied to a marine structure by a gas flow out of themarine structure by means of a linear test (e.g., hull form test) in awater tank or a wind tunnel and data about a response of the marinestructure according to the internal or external force to generate alook-up table, and storing the look-up table in a database; (2)measuring the internal or external force by using a time-of-flightmethod in an actual voyage of the marine structure and storing theinternal or external force in the database; (3) comparing themeasurement data of the internal or external force obtained in the step(2) with the data about the internal or external force accumulated inthe look-up table in the step (1) to predict data about a response ofthe marine structure; (3-1) measuring an actual response of the marinestructure; (3-2) comparing the data about a response of the marinestructure measured in the step (3-1) with the data about a response ofthe marine structure predicted in the step (3), and when the data abouta response of the marine structure measured in the step (3-1) does notagree with the data about a response of the marine structure predictedin the step (3), correcting the data about a response of the marinestructure stored in the look-up table generated in the step (1) into thedata about a response of the marine structure measured in the step(3-1); and (4) obtaining maintenance data about the marine structure byperforming virtual simulation to the data accumulated in the look-uptable.

In addition, the data about a response of the marine structure mayinclude at least one selected from the group consisting of strain,deformation, crack, vibration, frequency, corrosion, and erosion.

In addition, the maintenance data of the step (4) may be obtaineddistinguishably according to preset importance of individual structuresprovided at the marine structure.

In addition, the maintenance data may include at least one selected fromthe group consisting of maintenance-required location information,maintenance cost information, required maintenance time information andresidual life information of each structure.

Meanwhile, in another aspect of the present disclosure, there is alsoprovided a method for fuel savings and safe operation by real-timepredictive monitoring and predictive controlling of hydrodynamicenvironmental internal or external force, hull stresses, 6-dof motionand location of a marine structure, the method including: (1)accumulating data about an internal or external force applied to amarine structure by a fluid flow out of the marine structure by means ofa linear test (e.g., hull form test) in a water tank or a wind tunneland data about a response of the marine structure according to theinternal or external force to generate a look-up table, and storing thelook-up table in a database; (2) measuring the internal or externalforce by using a time-of-flight method in an actual voyage of the marinestructure and storing the internal or external force in the database;(3) comparing the measurement data of the internal or external forceobtained in the step (2) with the data about the internal or externalforce accumulated in the look-up table to predict data about a responseof the marine structure; and (4) controlling a posture or navigationpath of the marine structure in real time by using the predicted dataabout a response of the marine structure.

In addition, the step (3) may include (3-1) measuring an actual responseof the marine structure; and (3-2) when the data about a response of themarine structure measured in the step (3-1) does not agree with the dataabout a response of the marine structure predicted in the step (3), thedata about a response of the marine structure stored in the look-uptable generated in the step (1) is corrected into the data about aresponse of the marine structure measured in the step (3-1) or thecorrected data is applied to correct or supplement a numerical model.

In this case, the data about a response of the marine structure may becorrected by means of a simulator based on a numerical model includingcomputational fluid dynamics (CFD), finite element analysis (FEA),finite element method (FEM) and fluid structure interaction (FSI).

In addition, in the step (2), the internal or external force caused byfluid may be measured by using a measurement instrument provided at aside of the marine structure, and the measurement instrument may be anelectric sensor or an optical sensor.

In addition, in the step (2), the internal or external force applied tothe marine structure by a fluid flow may be actually measured by usingan internal measurement unit (IMU).

In addition, in the step (3), when the marine structure is a ship, thedata about a response of the marine structure may include at least oneselected from the group consisting of progress direction,four-directional slopes, sea gauge and trim of the ship.

In addition, in the step (3), when the marine structure is a temporarilyfixed structure, the data about a response of the marine structure mayinclude at least one selected from the group consisting of movingdirection, four-directional slopes and sea gauge of the temporarilyfixed structure.

In addition, in the step (2), directions and velocities of a tidalcurrent and a sea current according to space and time may be measuredfor each water level.

In addition, in the step (2), data including natural frequency, harmonicfrequency and fluid characteristics of the marine structure by a fluidflow may be measured.

In addition, in the step (1), the database storing the look-up table maybe a voyage data recorder (VDR) provided at the marine structure.

In addition, when the marine structure is a temporarily fixed structure,the look-up table may be recorded as time sequential data by the year,and the look-up table may be corrected by comparing with time sequentialdata by the year which have been accumulated till the previous year.

In addition, in the step (4), the posture or navigation path of themarine structure may be controlled in real time by using at least oneselected from the group consisting of a rudder, a thruster, a propeller,a sail, a kite and a balloon.

In addition, in the step (4), when the marine structure is a ship, adirection of a rudder and RPM of a thruster and a propeller may becontrolled according to the data about a response of the marinestructure so that a resultant force of a propelling force and theinternal or external force has a targeted progress direction.

In addition, when the marine structure is a temporarily fixed structure,a thruster may be controlled according to the predicted data about aresponse of the marine structure so that a resultant force of theinternal or external force is minimized and the thruster maintains acurrent location.

In addition, the marine structure may include a helideck, and in thestep (4), a center of gravity of the marine structure may be changed bycontrolling a posture of the marine structure or adjusting an 6-dofangle by means of dynamic positioning (DP) or dynamic motioning (DM) soas to maintain a balance of the helideck or relieve a shock when ahelicopter takes off or lands. In addition, the balanced stateinformation of the helideck according to the control of a posture of themarine structure may be stored in the database, the database maytransmit the balanced state information of the helideck to an externalstructure information server by means of a communication unit, and thestructure information server may provide location information of amarine structure, which has the balanced state information of thehelideck allowing taking-off or landing of a helicopter, among aplurality of marine structures.

In addition, in the steps (1) and (2), the data about the internal orexternal force applied to the marine structure by a fluid flow may bedata about vectors of a sea current and a tidal current, measured by apressure sensor installed at a side of the marine structure.

In addition, there may be provided a plurality of pressure sensorsinstalled at regular intervals at the side of the marine structure.

In addition, there may be provided a plurality of pressure sensors withdifferent heights at the side of the marine structure, and the presenceof measurement data obtained from the pressure sensors may be analyzedto obtain wave height data from data obtained from an uppermost pressuresensor.

In addition, among the plurality of pressure sensors, at least threepressure sensors may configure a three-dimensional pressure sensormodule, and the three-dimensional pressure sensor module may obtainthree-dimensional vector information of a sea current and a tidalcurrent.

In addition, the step (2) may further include (2-1) measuring at leastone selected from the group consisting of a wave intensity, a waveheight, a wave cycle, a wave velocity and a wave direction at a remotedistance from the marine structure by using a weather measurementinstrument, and storing the measurement data in the database, and theweather measurement instrument may include at least one selected fromthe group consisting of a wave radar, a directional wave rider, a sealevel monitor, an ultrasonic displacement sensor, an amemovane and anultrasonic wave-height meter.

In addition, the step (2) may further include (2-1) measuring at leastone selected from the group consisting of a wave intensity, a waveheight, a wave cycle, a wave velocity and a wave direction at a remotedistance from the marine structure by using a weather measurementinstrument, and storing the measurement data in the database.

In addition, the marine structure may include a ballast tank, andsloshing restraining units may be respectively provided at both sides ofthe ballast tank to reduce a sloshing phenomenon in the ballast tank. Inaddition, the sloshing restraining unit may restrain a sloshingphenomenon by decreasing an opening area of one horizontal section ofthe ballast tank.

In addition, in the step (4), ballast water loaded in the ballast tankmay be moved in a direction opposite to a slope to control a posture ofthe marine structure. In addition, the ballast tank may include abarrier for partitioning an inside of the ballast tank, and anopening/closing unit may be installed at the barrier to move the ballastwater to another partition, and a pump may be installed in theopening/closing unit to control a moving speed and a moving direction ofthe ballast water.

In addition, the measurement data of the internal or external forceobtained in the step (2) may be transmitted to an external weatherinformation server, and the weather information server may store weatherinformation correction data whose error is corrected by comparingweather information received from a satellite with the measurement dataof the internal or external force.

In addition, the weather information correction data may be provided toan external user terminal which accesses the weather information serveraccording to a request of the external user terminal.

Meanwhile, in another aspect of the present disclosure, there is alsoprovided a method for providing maintenance information by real-timepredictive monitoring of hydrodynamic environmental internal or externalforce, hull stresses, 6-dof motion and location of a marine structure,the method including: (1) accumulating data about an internal orexternal force applied to a marine structure by a fluid flow out of themarine structure by means of a linear test (e.g., hull form test) in awater tank or a wind tunnel and data about a response of the marinestructure according to the internal or external force to generate alook-up table, and storing the look-up table in a database; (2)measuring the internal or external force by using a time-of-flightmethod in an actual voyage of the marine structure and storing theinternal or external force in the database; (3) comparing themeasurement data of the internal or external force obtained in the step(2) with the data about the internal or external force accumulated inthe look-up table in the step (1) to predict data about a response ofthe marine structure; (3-1) measuring an actual response of the marinestructure; (3-2) comparing the data about a response of the marinestructure measured in the step (3-1) with the data about a response ofthe marine structure predicted in the step (3), and when the data abouta response of the marine structure measured in the step (3-1) does notagree with the data about a response of the marine structure predictedin the step (3), correcting the data about a response of the marinestructure stored in the look-up table generated in the step (1) into thedata about a response of the marine structure measured in the step(3-1); and (4) obtaining maintenance data about the marine structure byperforming virtual simulation to the data accumulated in the look-uptable.

In addition, the data about a response of the marine structure mayinclude at least one selected from the group consisting of strain,deformation, crack, vibration, frequency, corrosion, and erosion.

In addition, the maintenance data of the step (4) may be obtaineddistinguishably according to preset importance of individual structuresprovided at the marine structure.

In addition, the maintenance data may include at least one selected fromthe group consisting of maintenance-required location information,maintenance cost information, required maintenance time information andresidual life information of each structure.

According to the present disclosure, by introducing an opticalsensor-type measurement method, physical changes of a marine structuremay be monitored accurately.

In addition, according to the present disclosure, it is possible toprovide a monitoring system and method which may allow long-term stablemeasurement of a change of a marine structure by using an opticalsensor-type complex measurement, in comparison to an existing electricsensor-type measurement, and also ensure convenient installation andoperation.

Moreover, according to the present disclosure, since a marine structuremay be instantly maintained and repaired by monitoring the marinestructure in real time, costs required for operating the marinestructure may be reduced.

In addition, according to the present disclosure, by monitoring a marinestructure in real time, environmental pollution such as crude oil spillfrom the marine structure may be detected and prevented in advance.

According to the present disclosure, since aerodynamic and hydrodynamicenvironmental internal or external force, hull stresses, 6-dof motionand location of a marine structure which is voyaging or mooring may bemonitored or controlled in real time, the fuel consumed while the marinestructure is voyaging or mooring may be efficiently reduced.

In addition, by measuring a change of four-directional slopes, seagauge, trim or the like applied to a floating marine structure by meansof aerodynamic and hydrodynamic environmental internal or externalforce, the floating marine structure may be controlled safely.

Moreover, it is possible to provide an environment in which themonitoring information of the marine structure may be shared withanother external device to enhance the accuracy of weather information,and the system may serve as a ground true station capable of calibratingdata measured by satellites.

In addition, information monitored at the marine structure may beaccumulated and utilized for study on sea level rises caused by globalwarming and global environments such as energy budget change.

Moreover, by maintaining a balance of a helideck installed at the marinestructure, it is possible to give an environment which ensures rapidrescue using a helicopter at a marine accident.

In addition, weather information received from a satellite may becompared with measurement data of the internal or external force todecrease an error and then provided as basic data for forecast, therebycontributing to fishing industries.

Moreover, by providing information on maintenance according tocorrosion, erosion, crack, pressure, stress or the like caused byaerodynamic and hydrodynamic environmental internal or external forceapplied to the marine structure, it is possible to extend a life span ofthe marine structure for longer-term operation.

In addition, by analyzing static or dynamic characteristics of a marinestructure exposed to high-wave or strong-wind site conditions, it ispossible to give important data when preparing a medium- and long-termplan to ensure long-term stability of the marine structure.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram for illustrating a method for measuring a distancechange between a reference point and a point set on a marine structureby using an extensometer connected to a pipeline at the seabed accordingto an embodiment of the present disclosure.

FIG. 2 is a diagram showing a structure of an extensometer according toanother embodiment of the present disclosure.

FIG. 3 is a diagram showing an extensometer for measuring a lengthchange of a marine structure by providing an optical fiber wire whichconnects at least two points on the marine structure according toanother embodiment of the present disclosure.

FIG. 4 is a diagram for illustrating a method for measuring a lengthchange of the marine structure by means of trigonometrical survey byusing an extensometer according to another embodiment of the presentdisclosure.

FIG. 5 is a diagram showing that an automatic structure control unitchanges a location or angle of the marine structure according to thecontrol operation information according to another embodiment of thepresent disclosure.

FIG. 6 is a flowchart for illustrating a method for fuel savings andsafe operation by monitoring and controlling a marine structure withrespect to an aerodynamic and hydrodynamic environmental internal orexternal force applied to the marine structure of the presentdisclosure.

FIG. 7 is a diagram showing an aerodynamic vector applied to a marinestructure.

FIG. 8 is a diagram for illustrating a method for measuring anaerodynamic vector applied to a marine structure according to anembodiment of the present disclosure.

FIG. 9 is a diagram for illustrating a method for fuel savings and safeoperation by controlling a rudder when an internal or external force isapplied by means of aerodynamics according to an embodiment of thepresent disclosure.

FIGS. 10 and 11 are a cross-sectional view showing a ballast tankaccording to another embodiment of the present disclosure and a diagramshowing a barrier provided at the ballast tank and a structure of thebarrier.

FIG. 12 is a diagram showing maintenance data for a marine structure,which is schematized by means of simulation according to anotherembodiment of the present disclosure.

FIG. 13 is a diagram showing a marine structure (particularly, a ship)and a helideck installed at the marine structure.

FIG. 14 is a diagram showing that a pressure sensor is installed at amarine structure according to an embodiment of the present disclosure.

REFERENCE SYMBOLS

100: marine structure 200: marine structure 300: extensometer 301:winding unit 302: sensing unit 303: stimulating unit 304: optical sensor310: wire 320: optical fiber wire 400: automatic structure control unit410: coupling unit 420: displace adjusting unit 500: ballast tank 510:sloshing restraining unit 520: barrier 530: opening/closing unit 540:pump

DETAILED DESCRIPTION

Objects, technical configurations and resultant effects of the presentdisclosure will be clearly understood from the following detaileddescription based on drawings accompanied in the specification of thepresent disclosure. Embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings.

Embodiments disclosed in this specification should not be interpreted orused as limiting the scope of the present disclosure. It is obvious tothose skilled in the art that the descriptions including embodimentshave various applications. Therefore, unless it is limited by theclaims, the following embodiments are just examples for betterunderstanding of the present disclosure and are not intended to limitthe scope of the present disclosure.

The term “marine structure” used in the present disclosure has a widemeaning including all kinds of marine or submersible structures, forexample, jack-up rigs, semi-sub rigs, jackets, compliant towers, TLP,floating petroleum production, storing or extracting facilities, windpower generators and wave energy converters as well as directly orindirectly associated complex structures (e.g., non-subseastructures/flare towers, top-side), berthing-related marine structures,drill rigs, production casings for collecting oil and gas at anoilfield, flow lines, production lines, mooring lines, hawser lines,lowering lines, tethering cable lines for ROV, structure supports andconnection cables of sails for environment-friendly fuel savings,tensioners having an optical fiber embedded therein, blades and towersof a wind power generator, jackets, tensioners inserted into afoundation, bridge/cable-stayed bridge cables, structures such ason-water, in-water or under-water supports, and concrete tensioners forsuch structures. In addition, the term “marine structure” includescoupled risers and un-coupled risers. The coupled riser includes steelcatenary risers (SCRs), weight-distributed SCRs, steel lazy wave risers(SLWRs), flexible riser systems or the like, and the un-coupled riserincludes single hybrid riser towers, grouped SLOR, hybrid riser towers,buoyancy supported risers (commonly known as a BSR system) or the like.

1. Mathematical models include computational fluid dynamics (CFD),finite element method (FEM), fluid structure interaction (FSI), finitedifference method, finite volume method, inverse finite element method(iFEM), and inverse finite element analysis.

2. Wind, wave and current loads are calculated by means of computationalfluid dynamics (CFD).

3. A look-up table for wind, wave and current load response for fluidstructure interaction (FSI) and context cognitive information iscalculated.

4. Self-learning predictive monitoring and controlling, dynamicmonitoring system (DMS)/dynamic positioning system (DPS)/energyefficiency operational indicator (EEOI)/energy efficiency design index(EEDI) are accomplished by an artificial intelligence.

4-0-a. Dynamic positioning (DP) or dynamic motion (DM) boundary andpriority orders of target structures are applied to among individual orcomplex structures to minimize a fatigue, and helicopter taking-off orlanding, a separator, and a liquefying process are stabilized by meansof DMS.

4-0-b. when control is made to satisfy EEOI/EEDI conditions, priorityorders are applied to target structures among individual or complexstructures to determine a fatigue minimization priority order, thestructures are operated to ensure maximum control efficiency of DPS, DMSor EEOI, and quantitative EEDI is measured.

4-1. Calibrating numerical analysis with empirical data and evolvingand/or defining a specific algorithm (the artificial Intelligence) withNA (e.g., CFD/FEM/FSI) is performed in real time or as post-processing.

4-2. Diagnosis (e.g., diagnosis of a motion size, a fatigue of periodiccorrelation, a tension generated by deformation, displacement orlocation change, or posture of a marine structure, or a fatigueaccumulated therefrom) is performed in real time or as post-processing,and prognostic analysis is made based on the accumulated results.

4-3. Referring to core technique development of predictive maintenancefor optimal operation and maintenance of marine plants, a large amountof sensor data are processed and analyzed in real time for situationdiagnosis and prognosis.

The term ‘optical sensor’ used in this specification means a sensor forestimating a measured value by using intensity of light passing throughan optical fiber, refractive index, length or mode of the optical fiber,change of polarization state, or the like. In addition, a measurementvalue of the optical sensor is diverse, for example as temperature,pressure, strain, rotation rate or the like, and the optical sensor usessubstantially no electricity and has substantially no limit in its useenvironment due to excellent corrosion resistance of silica material.

In addition, the term ‘Bragg grating’ used in this specification means arefractive index variation pattern generated by changing an opticalrefractive index according to the degree of exposure when an opticalfiber is exposed to ultraviolet rays for a predetermined time. Inaddition, since an optical Bragg grating selectively reflects oreliminates light of a specific wavelength according to a variationperiod of the refractive index, the optical Bragg grating may be usedfor optical communication filters, optical distribution compensators,optical fiber laser or the like. In addition, by using the change oflight selectivity according to an external tensile force or temperaturechange, the optical Bragg grating is also widely applied as an opticalsensor.

In addition, the term ‘extensometer’ used in this specificationgenerally means a device for accurately changing a change of targetdistance, namely an elongation, and the term ‘inclinometer, used in thisspecification generally means a device for measuring a change of anglegenerated at a measurement target.

In addition, the term ‘numerical analysis’ used in this specificationmeans an analyzing method for numerically investigating a deformationbehavior by modeling a structure form or actual model with a computerprogram so that various variables such as stress applied thereto areused as input data and displace and stress states are used as outputdata, and this is an inclusive term including computational fluiddynamics, finite element method (FEM), fluid structure interaction(FSI), finite difference method (FDM), finite volume method (FVM),inverse finite element method (IFEM) or the like.

In addition, the term ‘finite element method (FEM)’ used in thisspecification means a numerical calculation method for dividing acontinuous structure into a finite number of elements having aone-directional rod, two-directional triangle or rectangle, orthree-dimensional solid body (a tetrahedron or a hexahedron) andperforming an approximation solution based on energy principles to eachregion.

In addition, the term ‘computational fluid dynamics (CFD)’ used in thisspecification means to calculate a dynamic motion of fluid or gas in anumerical analysis method by using a computer.

The present disclosure is directed to a system and method for measuringa buckling or walking phenomenon of a marine structure by using anoptical fiber and monitoring a physical change of the marine structureaccordingly, and the present disclosure uses a complex optical measuringinstrument including an extensometer capable of measuring a distancechange from a reference point at each location set on the marinestructure, an inclinometer capable of measuring a change direction ateach location set on the marine structure, or a seismometer capable ofdetecting a change of a reference point. In addition, a thermometer, aflow meter and a manometer may be included.

The present disclosure provides a system for monitoring a physicalchange of a marine structure, which includes a complex optical measuringinstrument for detecting a behavior and a structural change of themarine structure by using at least one optical sensor having an opticalfiber.

In addition, the complex optical measuring instrument includes anextensometer for measuring a distance change between at least onereference point set out of the marine structure and a point set on themarine structure by using the optical sensor, and the optical sensorchanges a wavelength of the optical signal passing through the opticalsensor according to a stress change applied to the optical fiber due tothe distance change.

Referring to FIG. 1, the extensometer includes at least one wire forconnecting the reference point and a point set on the marine structure.The wire may be fabricated as a tapeline made of invar which is an alloyhaving a low thermal expansion coefficient by adding 36.5% of nickel to63.5% of iron. By using an invar wire, the extensometer is used formeasuring a distance with high accuracy without being affected by anexternal temperature change.

In addition, referring to FIG. 2, the extensometer may further include awinding unit for winding the wire by a predetermined tension and asensing unit for measuring the number of revolutions of the winding unitby using the optical sensor. In addition, the extensometer may furtherinclude a stimulating unit for periodically stimulating the opticalsensor according to the number of revolutions measured by the sensingunit.

In addition, another embodiment of the present disclosure will bedescribed with reference to FIG. 3. Here, the complex optical measuringinstrument includes an extensometer having an optical fiber wireconnecting at least one point on the marine structure to measure alength change of the marine structure. The optical fiber wire changes awavelength of the optical signal passing through the optical sensoraccording to a stress change applied to the optical fiber due to thedistance change on the marine structure.

In addition, another embodiment of the present disclosure will bedescribed with reference to FIG. 4. Here, the extensometer includes atleast one wire installed at the same point on the structure and made ofan optical fiber, and the wire changes a wavelength of the opticalsignal passing through the optical sensor according to a stress changeapplied to the optical fiber due to the distance change on the marinestructure.

In addition, according to another embodiment of the present disclosure,the extensometer calculates the degree of tension of each wire by meansof the trigonometrical survey and provides absolute location informationof the point. Here, the trigonometrical survey means a method forfinding a coordinate and a distance of a point by using properties of atriangle. If this point is given together with two reference points, ina triangle formed by the point and two reference points, angles formedby a bottom side and other two sides are respectively measured, a lengthof the bottom side is measured, and then a series of calculations areperformed by using a sine law to find a coordinate and a distance of thepoint.

In addition, according to another embodiment of the present disclosure,the complex optical measuring instrument includes an inclinometer formeasuring an angle change between plural points on the marine structureby using the optical sensor. In addition, the inclinometer includes aweight installed in the gravity direction, and an optical sensorconnected to the weight and having at least one optical fiber, and dueto the angle change of the point on the marine structure where theinclinometer is installed, a wavelength of the optical signal passingthrough the optical fiber is changed according to a stress changeapplied to the optical fiber by means of the weight.

In addition, according to another embodiment of the present disclosure,the complex optical measuring instrument may further include aseismometer for measuring a location change of the reference point.Moreover, the complex optical measuring instrument may further include avibration gauge for measuring a vibration of the marine structure.

In addition, according to another embodiment of the present disclosure,a measurement device for detecting a change of the wavelength of theoptical signal by the complex optical measuring instrument may befurther included. A data logger or an interrogator may be used as themeasurement device.

In addition, according to another embodiment of the present disclosure,the complex optical measuring instrument detects a change of a targetstructure by using at least one of optical time-domain reflectometer(OTDR), Raman spectra (Raman), Brillouin scattering, Rayleigh wave,distributed acoustic sensing (DAS), acoustic emission, andinterferometry

In addition, according to another embodiment of the present disclosure,the measurement device may include an optical unit having a lasercapable of controlling a wavelength, an optical referencing unit fordistinguishing a wavelength of the optical signal reflected by theoptical unit by means of each optical sensor, an optical coupler forconnecting a plurality of optical fiber Bragg gratings of each opticalsensor output from the optical referencing unit and distributing a Braggreflection wavelength to each channel, and a photodiode for convertingthe Bragg reflection wavelength received from the optical coupler intoan electric signal. Moreover, the measurement device may have a functionof collecting scattered optical signals.

The extensometer measures an amount of behavior of the marine structureby detecting a length change between points set on the marine structure,and the inclinometer measures an angle change by detecting a directionof the behavior of the marine structure. The measured result istransferred to the measurement device by using a wired/wirelesselectric, electronic, sonar or optical communication method.

In order to measure buckling which is macroscopically generated over aseveral ten meters or several hundred meters in a direction horizontalto the seabed surface, a plurality of extensometers and inclinometersare provided to monitor a physical change of the marine structure.

If it is difficult to install a reference point at the seabed,extensometers are installed at intervals of 90 degrees, and an anglechange is monitored by using an inclinometer to monitor a physicalchange of the marine structure.

An extensometer capable of measuring a length change from the referencepoint and an inclinometer capable of measuring an angle change areprovided. At the reference point, a seismometer capable of measuringmovement of the ground may be further installed, and an opticalmeasurement device for receiving an optical signal from the inclinometerand the extensometer is also provided. The output from the measurementdevice is transmitted by using at least one of wired/wireless electric,electronic, sonar or optical communication methods so as to be checkedon the sea or remotely. In addition, a plurality of extensometers orinclinometers may be used.

In addition, at the reference point, a capable of measuring movement ofthe ground may be further installed, and an optical measurement devicefor receiving an optical signal from the inclinometer and theextensometer is also provided. The output from the measurement device istransmitted by using at least one of wired/wireless electric,electronic, sonar or optical communication methods so as to be checkedon the sea or remotely. In addition, a plurality of extensometers orinclinometers may be used.

Meanwhile, a method for monitoring a physical change of a marinestructure according to an embodiment of the present disclosure includes(a) changing a wavelength and/or light quantity of the optical signalpassing through an optical sensor according to a behavior or structuralchange of a marine structure by using at least one complex opticalmeasuring instrument installed on the marine structure or at a referencepoint, (b) by the complex optical measuring instrument, transmitting theoptical signal having the changed wavelength and/or light quantity tothe measurement device, and (c) by the measurement device, detecting achange of the wavelength and/or light quantity of the optical signal,and the complex optical measuring instrument includes at least oneoptical sensor using optical fiber Bragg grating.

In addition, another embodiment of the present disclosure will bedescribed with reference to FIG. 1. Here, the complex optical measuringinstrument may include an extensometer for measuring a distance changebetween at least one reference point set out of the marine structure anda point set on the marine structure.

In addition, another embodiment of the present disclosure will bedescribed with reference to FIG. 2. Here, the extensometer includes atleast one wire connecting the reference point and a point set on themarine structure, a winding unit for winding the wire by a predeterminedtension, a sensing unit for measuring the number of revolutions of thewinding unit by using an optical sensor, and a stimulating unit forperiodically stimulating the optical fiber according to the number ofrevolutions measured by the sensing unit.

In addition, another embodiment of the present disclosure will bedescribed with reference to FIG. 3. Here, the extensometer includes anoptical fiber wire 320 for connecting at least one point on the marinestructure to measure a length change of the marine structure, and theoptical fiber wire 320 changes a wavelength of the optical signalpassing through the optical fiber according to a stress change due to adistance change on the marine structure.

In addition, another embodiment of the present disclosure will bedescribed with reference to FIG. 4. Here, the extensometer includes atleast one wire installed on the same point on the marine structure andmade of an optical fiber, and the wire changes a wavelength of theoptical signal passing through the optical fiber according to a stresschange applied to the optical fiber due to a distance change on themarine structure.

In addition, according to another embodiment of the present disclosure,the extensometer provides absolute location information of the point bycalculating the degree of tension of each wire by means of thetrigonometrical survey.

In addition, according to another embodiment of the present disclosure,the complex optical measuring instrument includes an inclinometer formeasuring an angle change among a plurality of points on the marinestructure by using the optical sensor. The inclinometer includes aweight installed in the gravity direction and an optical sensorconnected to the weight, and the weight simulates the optical fiberaccording to an angle change occurring at the marine structure togenerate a stress change, and the generated stress change is convertedinto an optical signal.

In addition, according to another embodiment of the present disclosure,the complex optical measuring instrument further includes a seismometerfor measuring a location change of at least one reference point set outof the marine structure by using the optical sensor.

In addition, according to another embodiment of the present disclosure,the complex optical measuring instrument further includes a vibrationgauge for measuring a vibration of the marine structure.

In addition, according to another embodiment of the present disclosure,the measurement device may use a data logger or an interrogator.

In addition, according to another embodiment of the present disclosure,the measurement device may include an optical unit having a lasercapable of controlling a wavelength, an optical referencing unit fordistinguishing a wavelength of the optical signal reflected by theoptical unit by means of each optical sensor, an optical coupler forconnecting a plurality of optical fiber Bragg gratings of each opticalsensor output from the optical referencing unit and distributing a Braggreflection wavelength to each channel, and a photodiode for convertingthe Bragg reflection wavelength received from the optical coupler intoan electric signal.

Meanwhile, in another aspect, a controlling method by real-timemonitoring of a physical change of a marine structure includes (a)obtaining data about a physical change of a marine structure throughexperiments at a water tank or a wind tunnel and accumulating theobtained data to generate a look-up table, (b) obtaining about an actualphysical change of the marine structure, output from a measurementdevice, (c) comparing the data obtained in the step (b) with the dataaccumulated in the look-up table of the step (a) to generate forecastingdata about the physical change of the marine structure, and (d)generating maintenance information including at least one of structurecontrolling operation information, maintenance-required locationinformation, maintenance cost information and required maintenance timeand alarm information about gas leak, fire or explosion by means of athree-dimensional numerical analysis program which receives theforecasting data, and the physical change includes at least one of alength change, an angle change, a temperature change, a pressure changeand a specific volume change about at least one point on the marinestructure.

In addition, according to another embodiment of the present disclosure,after the step (c), the method further includes (c-1) comparing theforecasting data with data about an actual physical change of the marinestructure to correct the look-up table.

In addition, according to another embodiment of the present disclosure,after the step (d), the method further includes generating a simulatorwith the marine structure control information by means of a fluidstructure interaction (FSI) program, and associating the simulator withthe data about an actual physical change of the marine structure,obtained in the step (b), by means of context cognitive middleware togenerate an algorithm for automatically controlling the marinestructure.

In addition, according to another embodiment of the present disclosure,the three-dimensional numerical analysis program of the step (d) may usefinite element method (FEM) and computational fluid dynamics (CFD).

In addition, according to another embodiment of the present disclosure,in the step (d), the three-dimensional numerical analysis program may beassociated with a situation analysis module which stores virtualaugmented reality data about information such as gas leak, gasdiffusion, fire or explosion, which probably occurs according to abehavior and structural change of the marine structure, andcountermeasures against the virtual augmented reality data, to generatemaintenance information.

In addition, another embodiment of the present disclosure will bedescribed with reference to FIG. 5. Here, the method may further include(e) by an automatic structure control unit, controlling the marinestructure by changing a location or angle of the marine structureaccording to the control operation information, and the automaticstructure control unit may include a coupling unit connected to at leastone point on the marine structure and a displace adjusting unitconnected to the coupling unit to move the marine structure in fourdirections. By the automatic structure control unit, it is possible tocontrol the marine structure to have a minimal behavior and a minimalstructural change.

In addition, according to another embodiment of the present disclosure,the alarm information is generated by using the data about an actualphysical change of the marine structure, which is measured by themeasurement device by using at least one of tunable diode laserabsorption spectroscopy (TDLAS), distributed temperature sensing (DTS),distributed acoustic sensing (DAS), fiber Bragg grating (FBG) and remotemethane leak detector (RMLD).

The term ‘marine structure’ used in the present disclosure means, forexample, jack-up rigs, semi-sub rigs, jackets, compliant towers, TLP,floating petroleum production, storing or extracting facilities, windpower generators and wave energy converters as well as directly orindirectly associated complex structures (e.g., non-subseastructures/flare towers, top-side), berthing-related marine structures,drill rigs, production casings for collecting oil and gas at anoilfield, flow lines, production lines, mooring lines, hawser lines,lowering lines, tethering cable lines for ROV, structure supports andconnection cables of sails for environment-friendly fuel savings,tensioners having an optical fiber embedded therein, blades and towersof a wind power generator, jackets, tensioners inserted into afoundation, bridge/cable-stayed bridge cables, structures such ason-water, in-water or under-water supports, and concrete tensioners forsuch structures.

In the present disclosure, if a ship is operated in ballast withoutloading cargo, a propeller may float over the water surface, which maydeteriorate the propeller efficiency or damage the propeller, therebygiving a serious problem in safe navigation. In order to solve thisproblem a ballast tank is provided so that the ship may maintain aconstant sea gauge, and also the ballast tank allows the ship not tolose its stability even though cargo are loaded disproportionally. Inaddition, as the ballast tank, a water ballast filled with seawater isgenerally, but if the water ballast is insufficient, a solid ballastfilled with sand may also be used.

In the present disclosure, it is revealed that the measurementinstrument for measuring external forces (for example, wind load, waveload, current load) and reactions of a structure (for example,displacement, deformation, motion, vortex) has a broad meaning includinga lidar using electric or optical measurement methods, particle inducedvelocity (PVI), particle tracking velocity (PTV), a strain sensor, anextensometer, an accelerometer, an inclinometer, a pressure meter, aflow meter, a thermometer, a current meter, an acoustic emissionmonitor, a seismic trigger, a flow velocity sensor, a distributedtemperature sensor, a distributed strain sensor, an optical time-domainreflectometer (OTDR) or the like.

In the present disclosure, it is revealed that the measurementinstrument for measuring internal forces (for example, sloshing load,flow load, pressure load, thermal load) and reactions of a structure(for example, displacement, deformation, motion, walking, buckling,vortex) has a broad meaning including a lidar using an electric oroptical sensor, particle induced velocity (PVI), particle trackingvelocity (PTV), a strain sensor, an accelerometer, a current meter, anacoustic emission monitor, a seismic trigger, a flow velocity sensor, adistributed temperature sensor, a distributed strain sensor, an opticaltime-domain reflectometer (OTDR) or the like.

In addition, according to another embodiment of the present disclosure,the complex optical measuring instrument detects a change of a targetstructure by using at least one of optical time-domain reflectometer(OTDR), Raman spectra (Raman), Brillouin scattering, Rayleigh wave,distributed acoustic sensing (DAS), acoustic emission, andinterferometry

In the present disclosure, it is revealed that the time and spaceinformation and shape acquisition technique has a broad meaningincluding aerodynamic data collection methods using an RF- andmicrowave-GPS, DGPS, RTK, light-lidar, PIV, PIT, an interferometer orthe like.

In the present disclosure, it is revealed that the inertial measurementunit (IMU) has a broad meaning including acceleration and rotationmeasuring devices such as a gyro, a photo grid or the like. In addition,the gyro is a tool used for measuring a direction of an axiallysymmetric high-speed rotor in an inertial space or measuring an angularvelocity with respect to the inertial space, and the gyro is used formeasuring a direction and balance (inclination) of an airplane, a ship,a missile or the like to constantly keep a balance with a direction ofan airplane or ship in night operation.

In addition, the time and space information and shape acquisitiontechnique and the IMU are operated in association with 6-dof motion,posture reflex, localization and database of the marine structure tocontrol posture control by utilizing a monitoring system, an alarmingsystem and an automatic control system of the artificial intelligencefor EEOI/EEDI/DMS/DPS.

Prior to explaining the present disclosure, it is revealed thatmathematical models used in the present disclosure has a broad meaningincluding finite element method (FEM), gas structure interaction, finitedifference method, finite volume method, inverse finite element method(IFEM) or the like. Here, the finite element method (FEM) means anumerical calculation method for dividing a continuous structure into afinite number of elements having a one-directional rod, two-directionaltriangle or rectangle, or three-dimensional solid body (a tetrahedron ora hexahedron) and performing an approximation solution based on energyprinciples to each region.

In the present disclosure, if an agent converts situation informationinput by the same sensor as a USN sensor into middleware-dedicatedpackets and transmits the packets to context cognitive middleware, thecontext cognitive middleware receives and processes the packets in eachmodule classified based on a function and transmits the processingresult to a user program, thereby collecting all kinds of sensorinformation or controlling all kinds of equipment through an agent whichconverts monitored and controllable program situation information intomiddleware-dedicated packets. The middleware is modulated based on eachfunction (notifying, processing, storing, logging, controlling, JO,external application), and data are interlinked between modules by usinga middleware message defined with XML to ensure independency amongmodules. Therefore, it is revealed that the context cognitive middlewarehas a broad meaning including a correction function, an adding functionor the like.

In the present disclosure, the web-based context cognitive monitoringprogram has a program for monitoring situation information by using thecontext cognitive middleware and is also a web-based program which isavailable in a system where flash normally operates. It is revealed thatthe web-based context cognitive monitoring program has a broad meaningincluding programs for real-time monitoring (which allows graphpresentation, chart presentation), historical data inquiry of 10 minuteson average (for each period or sensor), setting a threshold value foreach sensor and alarming at threshold exceed, external program callingfor some sensors and result monitoring.

In the present disclosure, electric or optical measurement instrumentsare integrated to measure load, strain, deformation, displacement,fatigue, crack, vibration, frequency or the like of the marinestructure.

The force applied to a hull by the air is caused by three-dimensionalvelocity and direction, and responses in x, y and z axes with respect tox-, y- or z-axis incident angles are different from each other.

Referring to FIGS. 6 and 7, method for fuel savings and safe operationby real-time predictive monitoring and predictive controlling ofaerodynamic environmental internal or external force, hull stresses, 6degrees of freedom (6-dof) movement and location of a marine structureaccording to an embodiment of the present disclosure includes a step (1)of accumulating data about an internal or external force applied to amarine structure by a gas flow out of the marine structure by means of alinear test (e.g., hull form test) in a water tank or a wind tunnel anddata about a response of the marine structure according to the internalor external force to generate a look-up table, and storing the look-uptable in a database, a step (2) of measuring the internal or externalforce by using a time-of-flight method in an actual voyage of the marinestructure and storing the internal or external force in the database, astep (3) of comparing the measurement data of the internal or externalforce obtained in the step (2) with the data about the internal orexternal force accumulated in the look-up table in the step (1) topredict data about a response of the marine structure, and a step (4) ofcontrolling a posture or navigation path of the marine structure in realtime by using the predicted data about a response of the marinestructure.

Hull resistance caused by a change of sea gauge and trim is measured bymeans of a linear test (e.g., hull form test) in a water tank or a windtunnel and data, and aerodynamic energy to be applied to the ship ismeasured by using a radar, a pressure sensor, a strain sensor, anaccelerometer or the like in consideration of the influence of 6-dofmotion. In this case, direction and velocity of the gas at each altitudeare measured according to space and time.

In addition, according to the above steps, mathematical calculationmodels are associated with actual measurement data to perform automaticcontrol. Direction and velocity of aerodynamic energy to be applied tothe hull are measured in advance and applied to the hull, reactions ofthe marine structure are predicted by utilizing an aerodynamic reactionmodel test, the test results are compared with actual measurement data,the look-up table is corrected according to the comparison results todevelop an optimized aerodynamic reaction model, and then a posturecontrol or navigation path is determined accordingly.

In addition, the step (3) may further include (3-1) measuring an actualresponse of the marine structure, and (3-2) when the data about aresponse of the marine structure measured in the step (3-1) does notagree with the data about a response of the marine structure predictedin the step (3), correcting the data about a response of the marinestructure stored in the look-up table generated in the step (1) into thedata about a response of the marine structure measured in the step (3-1)or applying the corrected data to correct or supplement a numericalmodel (CFD and/or FEM).

In this case, the data about a response of the marine structure may becorrected by means of a simulator based on finite element analysis (FEA)or inversed finite element method (iFEM).

Regarding the data measured by the measurement instruments, a maximumcondition of the computational fluid dynamics (CFD) is input, andcorrelations between the behavior and 6-dof motion of the marinestructure and various physical values. The mathematical model results ofthe context cognitive middleware are associated with actual measurementdata to construct algorithm and simulation. By constructing a web-basedsystem through the context cognitive middleware and the web-basedcontext cognitive monitoring program, a monitoring and predictivecontrolling system of an artificial intelligence is constructed inaddition to a simple monitoring function.

Referring to FIG. 8, in the step (2), the internal or external forcecaused by gas may be measured by using a measurement instrument providedat the floating marine structure, and the measurement instrument may bean electric sensor or an optical sensor. In addition, the measurementinstrument may measure wind direction, wind velocity, atmosphericpressure, temperature, humidity and dust at each altitude.

In addition, in the step (2), the internal or external force applied tothe marine structure by a gas flow may be actually measured by using theIMU.

In addition, in the step (3), when the marine structure is a ship, aresponse of the marine structure may include at least one selected fromthe group consisting of progress direction, four-directional slopes, seagauge and trim of the ship.

In addition, in the step (3), when the marine structure is a temporarilyfixed structure, a response of the marine structure may include at leastone selected from the group consisting of moving direction,four-directional slopes and sea gauge of the temporarily fixedstructure.

In addition, in the step (2), data including natural frequency, harmonicfrequency and gas characteristics of the marine structure by a gas flowmay be measured.

In addition, in the step (1), the database storing the look-up table maybe a voyage data recorder (VDR) provided at the marine structure.

In addition, an electric or optical sensor may be attached to a mooringline, or a support and a connection cable (or, a sail line) of a sailfor environmental-friendly fuel savings to monitor a change ofaerodynamic coupled energy.

Measurement data about a stress measured at off-loading or approachingby inserting an optical fiber or an electric strain sensor into a hawserand a loading hose as well as 6-dof motion (heading, swaying, heaving,rolling, pitching, yawing motions) of the marine structure caused byaerodynamic environmental internal or external force are associated withstructural analysis, and the off-loading line is controlled in real timeor predictively in consideration of a priority order or importance ofsituation judgment to minimize a force (inertia and elasticity of pipelines, pumps, inserted tensioners, risers, mooring lines, hawsers, andoff-loading lines) applied by aerodynamics.

In addition, the data stored in the database may be utilized asreference data for implementing real-time context cognitive information,situation reproduction of a history recording and situation predictionin preparation for future predictive cases. In addition, the stored datamay be used for performing structure diagnosis and work evaluation bymeans of virtual simulation.

In addition, if the marine structure is a temporarily fixed structure,the look-up table may be recorded as time sequential data by the year,and the look-up table may be corrected by comparing with time sequentialdata by the year which have been accumulated till the previous year. Bydoing so, errors may be automatically reduced.

In addition, in the step (4), the posture or navigation path of themarine structure may be controlled in real time by using at least oneselected from the group consisting of a rudder, a thruster, a propeller,a sail, a kite and a balloon. In other words, a rudder or the like iscontrolled to minimize 6-dof motion, and if the marine structure isnavigating, a direction of the rudder is controlled to compensateaerodynamic force so that the marine structure may navigate in anoptimized path.

Meanwhile, if the marine structure is in operation, rolling may turnover the marine structure or drop cargo. In this case, if at least onekey is installed below the marine structure, rolling may be reduced bymeans of friction of the key.

Referring to FIG. 9, another embodiment of the present disclosure willbe described. In the step (4), if the marine structure is a ship, adirection of the rudder or a RPM of the thruster or propeller may becontrolled according to the data about a predicted response of themarine structure so that a resultant force of a propelling force and theinternal or external force has a targeted progress direction. Forexample, it may be found in FIG. 9 that a moving distance to a targetpoint is shortened when the rudder is controlled with respect to aninternal or external force applied to the ship by means of aerodynamics,in comparison to the case where the rudder installed at the ship is notcontrolled.

In addition, if the marine structure is a temporarily fixed structure, athruster may be controlled according to the predicted data about aresponse of the marine structure so that a resultant force with theinternal or external force is minimized to maintain a current location.

Referring to FIG. 13, the marine structure may include a helideck. Here,in the step (4), a center of gravity of the marine structure is changedby controlling a posture of the marine structure or adjusting an 6-dofangle by means of dynamic positioning (DP) or dynamic motioning (DM) soas to maintain a balance of the helideck or relieve a shock when ahelicopter takes off or lands, and balanced state information of thehelideck may be stored in the database.

In addition, the balanced state information of the helideck obtained bycontrolling a posture of the marine structure is stored in the database.Also, the database may transmit the balanced state information of thehelideck to an external structure information server through acommunication unit, and the structure information server may provide thehelicopter with location information of a marine structure, which hasthe balanced state information of the helideck allowing taking-off orlanding of a helicopter, among a plurality of marine structures. Inaddition, the 6-dof angle such as a trim may be adjusted to change thecenter of gravity of the marine structure and maintain a balanced stateso as to maintain a balance suitable for a targeted function (including,helicopter taking-off or landing, a separator, and a liquefying process)of the marine structure or relieve shocks. In particular, when ahelicopter takes off or lands, an impact at the marine structure orhelideck and the helicopter supporting structure may be relieved.

In addition, the step (2) may further include (2-1) measuring at leastone selected from the group consisting of wind direction, wind velocity,temperature, humidity, atmospheric pressure, solar radiant rays,inorganic ions, carbon dioxide, dust, radioactivity and ozone at aremote distance from the marine structure by using a measurementinstrument, and storing the measurement data in the database.

The measurement instrument may include at least one selected from thegroup consisting of an anemometer, a weathervane, a hygrometer, athermometer, a barometer, a solarimeter, an atmospheric gassol automaticcollector, a CO2 flux measurement instrument, an atmospheric dustcollector, an air sampler and an ozone analyzer.

In addition, by using the IMU, the time and space information and shapeacquisition technique and the radar capable of detecting X-band andS-band, collision with a dangerous article is prevented, and a winddirection, a wind velocity, an atmospheric pressure and a temperatureare predicted. In addition, by using at least one IMU, hogging, saggingand torsion as well as 6-dof motion of the marine structure aremeasured, and by using the time and space information acquisitiontechnique, a moving distance of the marine structure and environmentalinternal or external force data of a coordinate measuring satellite areassociated with the radar and IMU data to minimize a fatigue of themarine structure.

In addition, the number of polar images collected by the radar is notlimited to 32, and when a new polar image is received, a first or oldestpolar image is deleted to ensure real-time dynamic image processing. Bydoing so, collision with a dangerous article may be prevented, and awind velocity, a wind direction, an atmospheric pressure and atemperature may be predicted. In addition, an existing X-band or S-bandanti-collision radar is used by utilizing a radio frequency (RF) 1×2splitter or a RF amplifier. In addition, the influence caused by a 6-dofmotion is compensated with respect to the measurement data of the waveradar, and a time-of-flight method and an image overlay method are used.

Referring to FIG. 10, the marine structure may include a ballast tank,and sloshing restraining units respectively provided at both sides ofthe ballast tank to reduce a sloshing phenomenon in the ballast tank. Inaddition, the sloshing restraining unit restrains a sloshing phenomenonby decreasing an opening area of one horizontal section of the ballasttank.

In addition, referring to FIG. 11, in the step (4), when a slope occursin marine structure due to an aerodynamic internal or external force,ballast water loaded in the ballast tank is moved in a directionopposite to the slope to control a posture of the marine structure. Inaddition, the ballast tank may include a barrier for partitioning aninside of the ballast tank, and an opening/closing unit may be installedat the barrier to move the ballast water to another partition. Also, apump may be installed in the opening/closing unit to control a movingspeed and a moving direction of the ballast water. In addition, theballast tank may be connected to a water gauge to monitor a water levelof the ballast tank and perform active control by means of feeding-backand/or feeding-forward.

In addition, the measurement data of the internal or external forceobtained in the step (2) may be transmitted to an external weatherinformation server, and the weather information server may store weatherinformation correction data whose error is corrected by comparingweather information received from a satellite with the measurement dataof the internal or external force.

In addition, the weather information correction data may be provided toan external user terminal which accesses the weather information serveraccording to a request of the external user terminal.

Meanwhile, according to another embodiment of the present disclosure,there is also provided a method for providing maintenance information byreal-time predictive monitoring of aerodynamic environmental internal orexternal force, hull stresses, 6-dof motion and location of a marinestructure, which includes a step (1) of accumulating data about aninternal or external force applied to a marine structure by a gas flowout of the marine structure by means of a linear test (e.g., hull formtest) in a water tank or a wind tunnel and data about a response of themarine structure according to the internal or external force to generatea look-up table, and storing the look-up table in a database, a step (2)of measuring the internal or external force by using a time-of-flightmethod in an actual voyage of the marine structure, a step (3) ofcomparing the measurement data of the internal or external forceobtained in the step (2) with the data about the internal or externalforce accumulated in the look-up table in the step (1) to predict dataabout a response of the marine structure, a step (3-1) of measuring anactual response of the marine structure, a step (3-2) of comparing thedata about a response of the marine structure measured in the step (3-1)with the data about a response of the marine structure predicted in thestep (3), and if there is a difference, correcting the data about aresponse of the marine structure stored in the look-up table generatedin the step (1) into the data about a response of the marine structuremeasured in the step (3-1), a step (4) of obtaining maintenance dataabout the marine structure by performing virtual simulation to the dataaccumulated in the look-up table, and a step (5) of applying actualmeasurement data of the virtual simulation to compare a response resultvalue which is a result of the virtual simulation with real-time actualmeasurement value about a response of the marine structure, andcorrecting the data about a response of the marine structure or applyingthe corrected data to correct or supplement a numerical model.

Referring to FIG. 12, according to an embodiment of the presentdisclosure, data obtained by simulating the maintenance data may bechecked. For example, the maintenance data may include locationinformation, maintenance cost information, required maintenance timeinformation, residual life information or the like of individualstructures provided at the marine structure according to the importanceorder, when being output.

In addition, after the step (4), the method may further include a stepof generating a simulator with the marine structure control informationby means of a fluid structure interaction (FSI) program, and associatingthe simulator with the data about an actual response of the marinestructure, obtained in the step (3-1), by means of context cognitivemiddleware to generate an algorithm for automatically controlling themarine structure.

In addition, in the step (4), a three-dimensional numerical analysisprogram using finite element method (FEM) and computational fluiddynamics (CFD) is associated with a situation analysis module whichstores virtual augmented reality data about information including gasleak, gas diffusion, fire or explosion, which probably occurs accordingto a behavior and structural change of the marine structure, andcountermeasures against the virtual augmented reality data, to generatemaintenance information.

In addition, the data about a response of the marine structure mayinclude at least one selected from the group consisting of strain,deformation, crack, vibration, frequency, corrosion, and erosion. Thefrequency includes natural frequency and harmonic frequency and may beassociated with a structure analysis method to avoid a frequency appliedto the marine structure so as to be utilized as data for minimizing afatigue and elongating the life span.

In addition, the maintenance data of the step (4) may be obtaineddistinguishably according to preset importance of individual structuresprovided at the marine structure.

When control is made to satisfy a DP condition or a DP boundarycondition, a priority order in relation to fatigue minimization isdetermined for individual structures provided at the marine structure,and the individual structures may be operated in the order of emergent,urgent, preferential or the like to suitably enhance the efficiency ofEEOI/EEDI/DMS/DPS.

In addition, the maintenance data may include at least one selected fromthe group consisting of maintenance-required location information,maintenance cost information, required maintenance time information andresidual life information of each structure.

The data about a response of the marine structure by the predictedslamming and a response of the storage tank including the ballast tankare associated with mathematical models to obtain an optimizing andartificial intelligence algorithm, and the result is stored in a voyagedata recorder (VDR) or a separate server as a look-up table to control aposture of the marine structure and minimize a damage. In addition, thestored data is utilized as reference data for implementing real-timecontext cognitive information, situation reproduction of a historyrecording and situation prediction in preparation for future predictivecases. In addition, the stored data may be used for performing structurediagnosis and work evaluation by means of virtual simulation.

An optimized predictive simulator is implemented by successivelyapplying actual measurement data to the algorithm or simulator andcorrecting the look-up table. The algorithm or simulator may be appliedto a marine structure including risers (including a steel catenary riser(SCR), a top tensioned riser (TTR) and a tendon), a remotely operatedvehicle (ROV), a drill rig or the like to implement automation using anautomatic learning technique.

Referring to FIG. 6, a method for fuel savings and safe operation byreal-time predictive monitoring and predictive controlling ofhydrodynamic environmental internal or external force, hull stresses,6-dof motion and location of a marine structure according to anembodiment of the present disclosure includes a step (1) of accumulatingdata about an internal or external force applied to a marine structureby a fluid flow out of the marine structure by means of a linear test(e.g., hull form test) in a water tank or a wind tunnel and data about aresponse of the marine structure according to the internal or externalforce to generate a look-up table, and storing the look-up table in adatabase, a step (2) of, by a measurement instrument, measuring theinternal or external force by using a time-of-flight method in an actualvoyage of the marine structure and storing the internal or externalforce in the database, a step (3) of comparing the measurement data ofthe internal or external force obtained in the step (2) with the dataabout the internal or external force accumulated in the look-up table topredict data about a response of the marine structure, and a step (4) ofcontrolling a posture or navigation path of the marine structure in realtime by using the predicted data about a response of the marinestructure.

Hull resistance caused by a change of sea gauge and trim is measured bymeans of a linear test (e.g., hull form test) in a water tank or a windtunnel and data, and aerodynamic energy to be applied to the ship ismeasured by using a pressure sensor, a strain sensor, an accelerometeror the like in consideration of the influence of 6-dof motion. In thiscase, directions and velocities of a sea current and a tidal current ateach height are measured according to space and time.

In addition, according to the above steps, mathematical calculationmodels are associated with actual measurement data to perform automaticcontrol. Direction and velocity of hydrodynamic energy to be applied tothe hull are measured in advance and applied to the hull, reactions ofthe marine structure are predicted by utilizing a hydrodynamic reactionmodel test, the test results are compared with actual measurement data,the look-up table is corrected according to the comparison results todevelop an optimized hydrodynamic reaction model, and then a posturecontrol or navigation path is determined accordingly.

In addition, the step (3) may further include (3-1) measuring an actualresponse of the marine structure, and (3-2) when the data about aresponse of the marine structure measured in the step (3-1) does notagree with the data about a response of the marine structure predictedin the step (3), the data about a response of the marine structurestored in the look-up table generated in the step (1) is corrected intothe data about a response of the marine structure measured in the step(3-1) or the corrected data is applied to correct or supplement anumerical model.

In this case, the data about a response of the marine structure may becorrected by means of a simulator based on finite element analysis(FEA).

Regarding the data measured by the measurement instruments, a maximumcondition of the computational fluid dynamics (CFD) is input, andcorrelations between the behavior and 6-dof motion of the marinestructure and various physical values. The mathematical model results ofthe context cognitive middleware are associated with actual measurementdata to construct algorithm and simulation. By constructing a web-basedsystem through the context cognitive middleware and the web-basedcontext cognitive monitoring program, a monitoring and predictivecontrolling system of an artificial intelligence is constructed inaddition to a simple monitoring function.

In addition, in the step (2), the internal or external force caused byfluid may be measured by using a measurement instrument provided at aside of the floating marine structure, and the measurement instrumentmay be an electric sensor or an optical sensor

In addition, in the step (2), the internal or external force applied tothe marine structure by a fluid flow may be actually measured by usingan internal measurement unit (IMU).

In addition, in the step (3), when the marine structure is a ship, thedata about a response of the marine structure may include at least oneselected from the group consisting of progress direction,four-directional slopes, sea gauge and trim of the ship.

In addition, in the step (3), when the marine structure is a temporarilyfixed structure, the data about a response of the marine structure mayinclude at least one selected from the group consisting of movingdirection, four-directional slopes and sea gauge of the temporarilyfixed structure.

In addition, in the step (2), directions and velocities of a tidalcurrent and a sea current according to space and time may be measuredfor each water level.

In addition, in the step (2), data including natural frequency, harmonicfrequency and fluid characteristics of the marine structure by a fluidflow may be measured.

In addition, in the step (1), the database storing the look-up table maybe a voyage data recorder (VDR) provided at the marine structure.

In addition, an electric or optical sensor may be attached to a mooringline, or a support and a connection cable (or, a sail line) of a sailfor environmental-friendly fuel savings to monitor a change ofhydrodynamic coupled energy.

Measurement data about a stress measured at off-loading or approachingby inserting an optical fiber or an electric strain sensor into a hawserand a loading hose as well as 6-dof motion (heading, swaying, heaving,rolling, pitching, yawing motions) of the marine structure caused byhydrodynamic environmental internal or external force are associatedwith structural analysis, and the off-loading line is controlled in realtime or predictively in consideration of a priority order or importanceof situation judgment to minimize a force (inertia and elasticity ofpipe lines, pumps, inserted tensioners, risers, mooring lines, hawsers,and off-loading lines) applied by hydrodynamics.

In addition, the data stored in the database may be utilized asreference data for implementing real-time context cognitive information,situation reproduction of a history recording and situation predictionin preparation for future predictive cases. In addition, the stored datamay be used for performing structure diagnosis and work evaluation bymeans of virtual simulation.

In addition, if the marine structure is a temporarily fixed structure,the look-up table may be recorded as time sequential data by the year,and the look-up table may be corrected by comparing with time sequentialdata by the year which have been accumulated till the previous year. Bydoing so, errors may be automatically reduced.

In addition, in the step (4), the posture or navigation path of themarine structure may be controlled in real time by using at least oneselected from the group consisting of a rudder, a thruster, a propellerand a sail. In other words, a rudder or the like is controlled tominimize 6-dof motion, and if the marine structure is navigating, adirection of the rudder is controlled to compensate hydrodynamic forceso that the marine structure may navigate in an optimized path.

Meanwhile, if the marine structure is in operation, rolling may turnover the marine structure or drop cargo. In this case, if at least onekey is installed below the marine structure, rolling may be reduced bymeans of friction of the key.

In addition, another embodiment of the present disclosure will bedescribed with reference to FIG. 9. In the step (4), if the marinestructure is a ship, a direction of the rudder or a RPM of the thrusteror propeller may be controlled according to the data about a predictedresponse of the marine structure so that a resultant force of apropelling force and the internal or external force has a targetedprogress direction. For example, it may be found in FIG. 9 that a movingdistance to a target point is shortened when the rudder is controlledwith respect to an internal or external force applied to the ship bymeans of hydrodynamics, in comparison to the case where the rudderinstalled at the ship is not controlled.

In addition, if the marine structure is a temporarily fixed structure, athruster may be controlled according to the predicted data about aresponse of the marine structure so that a resultant force with theinternal or external force is minimized to maintain a current location.

In addition, referring to FIG. 13, the marine structure may include ahelideck. Here, in the step (4), a center of gravity of the marinestructure may be changed by controlling a posture of the marinestructure by means of dynamic positioning (DP) or dynamic motioning (DM)so as to maintain a balance of the helideck, and balanced stateinformation of the helideck may be stored in the database. In addition,the balanced state information of the helideck obtained by controlling aposture of the marine structure is stored in the database. Also, thedatabase may transmit the balanced state information of the helideck toan external structure information server through a communication unit,and the structure information server may provide the helicopter withlocation information of a marine structure, which has the balanced stateinformation of the helideck allowing taking-off or landing of ahelicopter, among a plurality of marine structures. In addition, the6-dof angle such as a trim may be adjusted to change the center ofgravity of the marine structure and maintain a balanced state so as tomaintain a balance suitable for a targeted function (including,helicopter taking-off or landing, a separator, and a liquefying process)of the marine structure or relieve shocks. In particular, when ahelicopter takes off or lands, an impact at the marine structure orhelideck and the helicopter supporting structure may be relieved.

In addition, in the steps (1) and (2), the data about the internal orexternal force applied to the marine structure by a fluid flow may bedata about vectors of a sea current and a tidal current, measured by apressure sensor installed at a side of the marine structure.

In addition, another embodiment of the present disclosure will bedescribed with reference to FIG. 14. In this embodiment, there may beprovided a plurality of pressure sensors installed at regular intervalsat the side of the marine structure. Meanwhile, in order to monitor awave applied to the marine structure, a three-dimensional pressuresensor module is installed at a side of the marine structure to analyzethe measured and extract vectors of a sea current and a tidal current.From this, it may be understood that a wave comes at an installationlocation of a sensor showing a greatest value. By doing so, a wavevelocity as well as a wave direction according to space and time may beanalogized by calculating a strain value by a wave.

In addition, the step (2) may further include (2-1) measuring at leastone selected from the group consisting of a wave intensity, a waveheight, a wave cycle, a wave velocity and a wave direction at a remotedistance from the marine structure by using a weather measurementinstrument, and storing the measurement data in the database, and theweather measurement instrument may include at least one selected fromthe group consisting of a wave radar, a directional wave rider, a sealevel monitor, an ultrasonic displacement sensor, an amemovane and anultrasonic wave-height meter.

In addition, another embodiment of the present disclosure will bedescribed with reference to FIG. 14. Here, there may be provided aplurality of pressure sensors with different heights at the side of themarine structure, and the presence of measurement data obtained from thepressure sensors may be analyzed to obtain wave height data from thedata obtained from an uppermost pressure sensor. In addition, a wavecycle may also be calculated by measuring a period of the measurementdata.

Meanwhile, another embodiment of the present disclosure will bedescribed with reference to FIG. 8. Here, the step (2) may furtherinclude (2-1) measuring at least one selected from the group consistingof a wave intensity, a wave height, a wave cycle, a wave velocity and awave direction at a remote distance from the marine structure by using awave radar 310, and storing the measurement data in the database. Byutilizing the wave radar 310, it is possible to calculate hydrodynamicsapplied to the marine structure by measuring a wave intensity, a waveheight, a wave cycle, a wave velocity or a wave direction from adistance of several hundred meters.

By using the IMU, the time and space information and shape acquisitiontechnique and the radar capable of detecting X-band and S-band,collision with a dangerous article is prevented, and a motion of a wavesuch as wave intensity or height is predicted. In addition, by using atleast one IMU, hogging, sagging and torsion as well as 6-dof motion ofthe marine structure are measured, and by using the time and spaceinformation acquisition technique, a moving distance of the marinestructure and environmental internal or external force data of acoordinate measuring satellite are associated with the radar and IMUdata to minimize a fatigue of the marine structure.

In addition, the number of polar images collected by the wave radar isnot limited to 32, and when a new polar image is received, a first oroldest polar image is deleted to ensure real-time dynamic imageprocessing. By doing so, collision with a dangerous article may beprevented, and a motion of a wave such as wave intensity or height maybe predicted. In addition, an existing X-band or S-band anti-collisionradar is used by utilizing a radio frequency (RF) 1×2 splitter or a RFamplifier. In addition, the influence caused by a 6-dof motion iscompensated with respect to the measurement data of the wave radar, anda time-of-flight method and an image overlay method are used.

In addition, another embodiment of the present disclosure will bedescribed with reference to FIG. 10. Here, the marine structure mayinclude a ballast tank, and sloshing restraining units respectivelyprovided at both sides of the ballast tank to reduce a sloshingphenomenon in the ballast tank. In addition, the sloshing restrainingunit restrains a sloshing phenomenon by decreasing an opening area ofone horizontal section of the ballast tank.

In addition, another embodiment of the present disclosure will bedescribed with reference to FIG. 11. Here, in the step (4), when a slopeoccurs in marine structure, ballast water loaded in the ballast tank maybe moved in a direction opposite to the slope to control a posture ofthe marine structure. In addition, the ballast tank may include abarrier for partitioning an inside of the ballast tank, and anopening/closing unit may be installed at the barrier to move the ballastwater to another partition. Also, a pump may be installed in theopening/closing unit to control a moving speed and a moving direction ofthe ballast water. In addition, the ballast tank may be connected to awater gauge to monitor a water level of the ballast tank and performactive control by means of feeding-back and/or feeding-forward.

In addition, the measurement data of the internal or external forceobtained in the step (2) may be transmitted to an external weatherinformation server, and the weather information server may store weatherinformation correction data whose error is corrected by comparingweather information received from a satellite with the measurement dataof the internal or external force.

In addition, the weather information correction data may be provided toan external user terminal which accesses the weather information serveraccording to a request of the external user terminal.

Meanwhile, according to another embodiment of the present disclosure,there is also provided a method for providing maintenance information byreal-time predictive monitoring of hydrodynamic environmental internalor external force, hull stresses, 6-dof motion and location of a marinestructure, which includes a step (1) of accumulating data about aninternal or external force applied to a marine structure by a fluid flowout of the marine structure by means of a linear test (e.g., hull formtest) in a water tank or a wind tunnel and data about a response of themarine structure according to the internal or external force to generatea look-up table, a step (2) of measuring the internal or external forceby using a time-of-flight method in an actual voyage of the marinestructure, a step (3) of comparing the measurement data of the internalor external force obtained in the step (2) with the data about theinternal or external force accumulated in the look-up table in the step(1) to predict data about a response of the marine structure, a step(3-1) of measuring an actual response of the marine structure, a step(3-2) of comparing the data about a response of the marine structuremeasured in the step (3-1) with the data about a response of the marinestructure predicted in the step (3), and if there is a difference,correcting the data about a response of the marine structure stored inthe look-up table generated in the step (1) into the data about aresponse of the marine structure measured in the step (3-1), and a step(4) of obtaining maintenance data about the marine structure byperforming virtual simulation to the data accumulated in the look-uptable.

Referring to FIG. 12, according to an embodiment of the presentdisclosure, data obtained by simulating the maintenance data may bechecked. For example, the maintenance data may include locationinformation, maintenance cost information, required maintenance timeinformation, residual life information or the like of individualstructures provided at the marine structure according to the importanceorder, when being output.

In addition, the data about a response of the marine structure mayinclude at least one selected from the group consisting of strain,deformation, crack, vibration, frequency, corrosion, and erosion. Thefrequency includes natural frequency and harmonic frequency and may beassociated with a structure analysis method to avoid a frequency appliedto the marine structure so as to be utilized as data for minimizing afatigue and elongating the life span.

In addition, the maintenance data of the step (4) may be obtaineddistinguishably according to preset importance of individual structuresprovided at the marine structure.

When control is made to satisfy a DP condition or a DP boundarycondition, a priority order in relation to fatigue minimization isdetermined for individual structures provided at the marine structure,and the individual structures may be operated in the order of emergent,urgent, preferential or the like to suitably enhance the efficiency ofEEOI/EEDI/DMS/DPS.

In addition, the maintenance data may include at least one selected fromthe group consisting of maintenance-required location information,maintenance cost information, required maintenance time information andresidual life information of each structure.

An electric or optical sensor is inserted into at least one point of afloating mat assembly to measure load, strain, deformation,displacement, fatigue, micro crack, vibration and frequency of thefloating mat assembly, caused by sloshing. An electric or optical sensoris also inserted between walls of a fluid storage tank to measure load,strain, deformation, displacement, fatigue, micro crack, vibration andfrequency, caused by an impact between the floating mat and the wall ofthe fluid storage tank by sloshing.

A floating mat unit has a structure or material floatable in liquid suchas LNG and is applicable to a LNG tank, a ballast tank or the like. Thefloating mat is sized in consideration of a maximum amount of substancefilling the tank and also minimizes sloshing as well as an impact to themat and the tank by the sloshing.

Even though the measurement on the marine structure and the tank isimportant, since a response of the marine structure by slamming is notalways constant, an electric or optical sensor is inserted to measureload, strain, deformation, displacement, fatigue, micro crack, vibrationand frequency of the floating mat assembly, caused by sloshing, and thenthe measurement data is utilized as data for minimizing an impactbetween the marine structure and the tank by means of safety diagnosisand control.

The data about a response of the marine structure by the measuredslamming and a response of the storage tank including the ballast tankare associated with mathematical models to obtain an optimizing andartificial intelligence algorithm, and the result is stored in a voyagedata recorder (VDR) or a separate server as a look-up table to control aposture of the marine structure and minimize a damage. In addition, thestored data is utilized as reference data for implementing real-timecontext cognitive information, situation reproduction of a historyrecording and situation prediction in preparation for future predictivecases. In addition, the stored data may be used for performing structurediagnosis and work evaluation by means of virtual simulation.

An optimized predictive simulator is implemented by successivelyapplying actual measurement data to the algorithm or simulator andcorrecting the look-up table. The algorithm or simulator may be appliedto a marine structure including risers (including a steel catenary riser(SCR), a top tensioned riser (TTR) and a tendon), a remotely operatedvehicle (ROV), a drill rig or the like to implement automation using anautomatic learning technique.

A controlling method by real-time monitoring of hydrodynamicenvironmental internal or external force, hull stresses, 6-dof motionand location of a marine structure according to an embodiment of thepresent disclosure includes measuring a wave intensity and a wave heightand predicting a wave motion as well as preventing collision by using aradar, an internal measurement unit (IMU), a global positioning system(GPS) measurement technique and an X-band radar, measuring hogging,sagging and torsion as well as 6-dof motion of a marine structure byusing at least one IMU, associating data about a moving distance of themarine structure and environmental external force of a coordinatemeasuring satellite with the data of the radar and the IMU by using atime and space information obtaining tool to minimize a fatigue of themarine structure, and applying to an energy efficiency operatingindicator (EEOI), an energy efficiency design index (EEDI), a dynamicpositioning (DP) boundary, a motion controlling (MC) boundary, risers(including a steel catenary riser (SCR), a top tensioned riser (TTR) anda tendon), a lowering line, a remotely operated vehicle (ROV) and adrill rig to substitute an algorithm and a simulator of a predictionprocedure. In addition, a wave height, a wave intensity, a wave period,a wave velocity and a wave direction may be measured by using a radar,the number of polar images collected by the radar may not be limited to32, and when a new polar image is received, a first or oldest polarimage may be deleted to ensure real-time dynamic image processing. Inaddition, a collision prevention function, a wave intensity and heightmeasurement function and a wave motion prediction function may beassociated. Moreover, measurement results of a wave intensity, a waveheight, a wave period and a wave direction may be extracted by using anexisting X-band or S-band anti-collision radar and utilizing a radiofrequency (RF) 1×2 splitter, a RF amplifier or an optical signaltransmission and amplification function. In addition, a 6-dof motioncompensated X/S-Band wave radar, a wave height measuring sensor, aDoppler, a time-of-flight and image overlay method may be used.

1. A time and space information acquisition tool (for example, byutilizing an RF- and microwave-GPS, DGPS, RTK, light-lidar, PIV, PIT, aninterferometer or the like, and in the water, by utilizing sonic wave,ultrasonic wave, light/lidar or the like) and a smart IMU (including anartificial intelligence in which electric/photoelectric gyro+electricacceleration such as photo grid and MEM+environmental external forcemeasurement are associated, indirectly associated or non-associated(direct and indirect experience) and DB of context cognitive informationare associated with 6-dof motion/reaction response measurement and adatabase (DB) which recognizes situations of a marine structure, andmotion control is performed to utilize a predictive monitoring system, apredictive adviser system, and/or a predictive automated control systemfor an energy efficiency operating indicator (EEOI), a dynamicpositioning system (DPS) and a dynamic monitoring system (DMS) of anartificial intelligence associated or non-associated with environmentalexternal force measurement.

(1) When control is made to satisfy a DP condition or a DP boundarycondition, a priority order is applied to structures and complexstructures (for example, the priority order is firstly given to subseastructures/risers/drill rigs/hawser lines and/or mooring lines, and thennon-subsea structures/flare towers, top-sides, and hulls, . . . ) todetermine a priority order for minimizing a fatigue, and the marinestructures are operated to ensure maximum control efficiency of DPS, DMSor EEOI.

(2) When control is made to satisfy EEOI/EEDI conditions, a priorityorder is applied to structures and complex structures (for example,rudders, thrusters, propeller RPM, ballistic, fuel and/or storage tanks,wind sails, mooring line tensioners, risers and/or their tensioners) todetermine a priority order for minimizing a fatigue, and the marinestructures are operated to ensure maximum control efficiency of DPS orEEOI, or quantitative EEDI is measured.

(3) A drill rig/riser is monitored to set a most convenient posture of amarine structure and perform predictive control, and damping isperformed in consideration of necessary 6-dof at a necessary time (forexample, motion damping is performed based on heaves at a connectionportion, and a hydraulic motor is controlled in advance in considerationof a predicted motion to perform necessary damping in consideration of6-dof motion).

2. A life span of a structure is elongated by avoiding inherent responsefrequency (natural frequency or harmonic frequency) of individual orintegrated marine complex structures according to hydrodynamic andaerodynamic influences applied to the structure or changing a conditionof an environmental external force applied to the structure.

(1) A life span of a structure is elongated by minimizing a yield stressand a fatigue independently or complexly applied to the structureaccording to importance or a priority order on circumstantial judgmentby means of real-time measurement of an environmental external forceapplied to a structure, a complex energy applied to a complex structureand inertial and elastic kinetic energy possessed by the structure andassociation of calculated numerical results and 6-dof motion prediction.

3. Condition-based maintenance is allowed by measuring integrity of amooring line and accurately predicting a life span of the mooring line(for example, by utilizing static and dynamic numerals and change ratesof tension, strain, elongation, vibration or the like, and theiracceleration) to extract the integrity in real time, and unusual cold isreflected to control static and dynamic positioning of a marinestructure in a manual or automatic way and manage operations by applyinga residual fatigue.

(1) In mooring, mooring line tension monitoring is associated to controla motion and posture of a structure in consideration of environmentalexternal force-applied DP predictive monitoring and predictivecontrolling, MC predictive monitoring and predictive controlling, andEEOI.

(2) Optical measurement vibration (including DAS) is measured andapplied to a seabed structure (for example, mooring lines, risers,umbilical line structures) to measure a vibration of the structure andextract a deformation rate of the structure through existing strain oracceleration measurement, an environmental external force (including avector of an external force of a tidal current or a sea current) appliedin association with a deformation state, and a vector of a resultantresponse of the structure.

(3) When measurement of an environmental external force is associated, acontext cognitive function is predicted and stored in a DB by inputtinga maximum condition to CFD, FEA and/or FSI, and CFD, FEA, coupledresponse models and FSI (an environmental external force and a structuremotion model responding to the environmental external force) areutilized.

4. A measurement result for circumstance recognition required forimplementing real-time context cognitive information, situationreproduction of a history recording and situation prediction inpreparation for future predictive cases is acquired and stored in a DB.

(1) A real-time web-based system is constructed by utilizing contextcognitive middleware and a web-based context cognitive monitoringprogram.

(2) A context cognitive middleware or a software having a similarfunction is associated with measurement results of all context cognitivefunctions to serve as a base tool for optimizing mathematical models(including CFD, FEA and/or FSI), and the optimized mathematical modelsevolves to an algorithm and simulation to which actual measurement isapplied.

(3) An algorithm to which actual measurement or numerical calculation isapplied is associated in addition to a simple measurement monitoringfunction to implement a predictive monitoring and predictive controllingsystem or simulation configured as an artificial intelligence.

(4) A database having integrated measurement for context cognitiveinformation is stored in or associated with a voyage data recorder (VDR)to extract hydrodynamic and/or aerodynamic energy (for example, a wavedirection, a wind velocity, a vector of the wind direction and the windvelocity, and a vector of a resultant response of the structure).

5. A radar+IMU+GPS measurement technique and an X-band or S-band radaris used to prevent a collision as well as measure a wave intensity and awave height and predict a wave motion, at least one IMU is used tomeasure hogging, sagging and torsion as well as 6-dof motion of thehull, a time and space information acquisition tool (for example, byutilizing an RF- and microwave-GPS, DGPS, RTK, light-lidar, PIV, PIT, aninterferometer or the like, and in the water, by utilizing sonic wave,ultrasonic wave, light/lidar or the like) is used to minimize a fatigueof the hull by associating a moving distance of the ship andenvironmental external force data of a coordinate measuring satellitewith the data of the radar and the IMU, and this is applied to an energyefficiency operating indicator (EEOI), an energy efficiency design index(EEDI), a dynamic positioning (DP) boundary, a dynamic monitoring (DM)boundary, risers (including a steel catenary riser (SCR), a toptensioned riser (TTR) and a tendon), a lowering line, a remotelyoperated vehicle (ROV) and a drill rig to substitute an algorithm and asimulator of a prediction procedure.

(1) A wave height, a wave intensity, a wave period, a wave velocity anda wave direction may be measured by using a radar, the number of polarimages collected by the radar may not be limited to 32, and when a newpolar image is received, a first or oldest polar image may be deleted toensure real-time dynamic image processing.

(2) A collision prevention function, a wave intensity and heightmeasurement function and a wave motion prediction function may beassociated.

(3) An existing X-band or S-band anti-collision radar is used byutilizing a radio frequency (RF) 1×2 splitter or a RF amplifier.

(4) A 6-dof motion compensated X-band wave radar, a Doppler, atime-of-flight and image overlay method are used.

6. A simulation result (by hydrodynamic and aerodynamic information) ofmathematical models (including CFD, FEA and/or FSI) is applied to CDFanalysis to evolve for CDF model optimization and algorithm, theanalyzed and evolved result is accumulated as a look-up table in a VDRor a separate server, and the accumulated data is applied to virtualsimulation to perform structure diagnosis and work evaluation.

(1) Predictive control is performed by utilizing experienced referencedata.

(2) A black box function is added to configure a wire/wireless network.

(3) A corrected time tag function is added.

(4) A structure analysis algorithm function for comparing data measuredby an environmental monitoring system (EMS) and a motion monitoringsystem (MMS) including an accumulated artificial intelligence is added.

(5) A monitoring function and a predictive controlling system processed(utilizing the resulted influence to 6-dof motion and displacement forDPS, DMS and EEOI/EEDI) by applying the algorithm with actualmeasurement as an artificial intelligence is stored and recorded inaddition to a simple measurement monitoring function.

7. An optical & and electric extensometer, particle induced velocity(PIV), particle tracking velocity (PTV), band-pass (BP) filter energyintensity, strain gage, pressure sensor, ultrasonic measurement, andDAS-excitation and monitoring are used for hydro-elastic slamming and/orsloshing and aero-elastic fire/explosion measurement instrument.

(1) A deformation of a barrier is measured using a strain sensor andmonitored by means of ultrasonic measurement or DAS-excitation forglobal measurement.

(2) A response of a ship barrier by a wave is measured, and a locationof the measured sensor is checked to extract a wave height.

8. As a monitoring technique using a sensor (including strain,acceleration and temperature sensors) embedded in a structure, atensioner is inserted into a structure including bridges, seweragesystems, waterworks, gas pipes, oil tubes, tunnels and structuresupports, and vibration, acceleration, location, all-year or seasontemperature and properties (including stress or stiffness) are measuredusing the sensor inserted into the tensioner to diagnose safety of thestructure and monitor earthquake, water leak and robbery.

9. As a leakage accident influence evaluation interpretation techniquefor ensuring safety of a structure or pipe exposed for a predeterminedperiod due to another construction including subway and underground roadway construction, a gas explosion damage prediction at a closed orpartially opened space is interpreted using a computational fluiddynamics (CFD) theory.

What is claimed is:
 1. A method for controlling an operation of a marinestructure, the method comprising: (1) accumulating, by a computer, dataabout an internal or external force applied to the marine structure by afluid flow out of the marine structure by means of a linear test in awater tank or a wind tunnel, accumulating, by the computer, data about aresponse of the marine structure according to the internal or externalforce, generating by the computer, a look-up table based on theaccumulated data, and storing, by the computer, the look-up table in adatabase; (2) measuring, by one or more sensors, the internal orexternal force applied to the marine structure by using a time-of-flightmethod in an actual voyage of the marine structure and storing, by thecomputer, information relating to the internal or external force appliedto the marine structure in the database; (3) generating, by thecomputer, a predicted response of the marine structure to the internalor external force applied to the marine structure based on a comparisonof the measured data of the internal or external force applied to themarine structure obtained in the step (2) with the accumulated dataabout the internal or external force applied to the marine structureobtained in the step (1); and (4) controlling, by the computer, aposture or navigation path of the marine structure in real timeaccording to the predicted response of the marine structure to theinternal or external force applied to the marine structure.
 2. Themethod according to claim 1, wherein the step (2) further includes (2-1)measuring at least one selected from the group consisting of a waveintensity, a wave height, a wave cycle, a wave velocity or a wavedirection at a remote distance from the marine structure by using aweather measurement instrument, or storing the measurement data in thedatabase, and wherein the weather measurement instrument includes atleast one selected from the group consisting of a wave radar, adirectional wave rider, a sea level monitor, an ultrasonic displacementsensor, an amemovane or an ultrasonic wave-height meter.
 3. The methodaccording to claim 1, wherein the step (3) includes: (3-1) measuring anactual response of the marine structure; and (3-2) when the data about aresponse of the marine structure measured in the step (3-1) does notagree with the data about a response of the marine structure predictedin the step (3), correcting the data about a response of the marinestructure stored in the look-up table generated in the step (1) into thedata about a response of the marine structure measured in the step (3-1)or applying the corrected data to correct or supplement a numericalanalysis.
 4. The method according to claim 1, wherein the data about aresponse of the marine structure is corrected by means of a simulatorbased on one of a numerical model including computational fluid dynamics(CFD), finite element analysis (FEA), finite element method (FEM) andfluid structure interaction (FSI).
 5. The method according to claim 1,wherein in the step (2), the internal or external force caused by fluidis measured by using a measurement instrument provided at the marinestructure, and the measurement instrument is an electric sensor or anoptical sensor.
 6. The method according to claim 5, wherein ameasurement instrument capable of measuring wind direction, windvelocity, atmospheric pressure, temperature, humidity or dust at eachaltitude is further provided.
 7. The method according to claim 1,wherein in the step (2), the internal or external force applied to themarine structure by a fluid flow is actually measured by using aninternal measurement unit (IMU).
 8. The method according to claim 1,wherein in the step (3), when the marine structure is a ship, the dataabout a response of the marine structure includes at least one selectedfrom the group consisting of progress direction, four-directionalslopes, sea draft gauge, and trim of the ship.
 9. The method accordingto claim 1, wherein in the step (3), when the marine structure is atemporarily fixed (stationary kept floating) structure, the data about aresponse of the marine structure includes at least one selected from thegroup consisting of moving direction, four-directional slopes and seadraft gauge of the temporarily fixed structure.
 10. The method accordingto claim 1, wherein in the step (2), data including natural frequency,harmonic frequency or fluid characteristics of the marine structure by afluid flow is measured, and directions and velocities of a tidal currentor a sea current according to space or time are measured for each waterlevel.
 11. The method according to claim 1, wherein in the step (1), thedatabase storing the look-up table is a voyage data recorder (VDR)provided at the marine structure.
 12. The method according to claim 1,wherein when the marine structure is a temporarily fixed (stationarykept floating) structure, the look-up table is recorded as timesequential data by the year, and the look-up table is corrected bycomparing with time sequential data by the year which have beenaccumulated till the previous year.
 13. The method according to claim 1,wherein in the step (4), the posture or navigation path of the marinestructure is controlled in real time by using at least one selected fromthe group consisting of a rudder, a thruster, a propeller, a sail, akite or a balloon.
 14. The method according to claim 1, wherein in thestep (4), when the marine structure is a ship, a direction of a rudderor a RPM of a thruster or propeller is controlled according to the dataabout a response of the marine structure so that a resultant force of apropelling force and the internal or external force has a targetedprogress direction.
 15. The method according to claim 1, wherein whenthe marine structure is a temporarily fixed (stationary kept floating)structure, a thruster is controlled according to the predicted dataabout a response of the marine structure so that a resultant force ofthe internal or external force is minimized and the thruster maintains acurrent location.
 16. The method according to claim 1, wherein themarine structure includes a helideck, wherein in the step (4), a centerof gravity of the marine structure is changed by controlling a postureof the marine structure or adjusting an 6-dof angle by means of dynamicpositioning (DP) or dynamic motioning (DM) so as to maintain a balanceof the helideck or relieve a shock when a helicopter takes off or lands,and balanced state information of the helideck is stored in thedatabase, and wherein the 6-dof angle including trim is adjusted tochange the center of gravity of the marine structure and maintain abalanced state so as to maintain a balance suitable for a targetedfunction of the marine structure.
 17. The method according to claim 1,wherein the step (2) further includes (2-1) measuring at least oneselected from the group consisting of wind direction, wind velocity,temperature, humidity, atmospheric pressure, solar radiant rays,inorganic ions, carbon dioxide, dust, radioactivity or ozone at a remotedistance from the marine structure by using a measurement instrument, orstoring the measurement data in the database, and wherein themeasurement instrument includes at least one selected from the groupconsisting of an anemometer, a weathervane, a hygrometer, a thermometer,a barometer, a solarimeter, an atmospheric gassol automatic collector, aCO2 flux measurement instrument, an atmospheric dust collector, an airsampler or an ozone analyzer.
 18. The method according to claim 1,wherein the marine structure includes a ballast tank, and sloshingrestraining units are respectively provided at both sides of the ballasttank to reduce a sloshing phenomenon in the ballast tank.
 19. The methodaccording to claim 18, wherein the sloshing restraining unit restrains asloshing phenomenon by decreasing an opening area of one horizontalsection of the ballast tank.
 20. The method according to claim 1,wherein the marine structure includes a ballast tank, wherein theballast tank includes a barrier for partitioning an inside of theballast tank, and wherein an opening/closing unit is installed at thebarrier to move the ballast water to another partition, and a pump isinstalled in the opening/closing unit to control a moving speed and amoving direction of the ballast water.
 21. The method according to claim1, wherein the measurement data of the internal or external forceobtained in the step (2) is transmitted to an external weatherinformation server, or the weather information server stores weatherinformation correction data whose error is corrected by comparingweather information received from a satellite with the measurement dataof the internal or external force.